sex

/sɛks/

//sɛks// noun

"sex" is a 3-letter English headword indexed on PlainSpell.

The verdict

“sex” sits in 20 confusable pairs (corpus #611) as a noun. The look-alike neighbours are the real trap.

#611
frequency rank, English
6,566
“S” headwords
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A category into which sexually-reproducing organisms are divided on the basis of their reproductive roles in their species; the system of such categories, which can differ by organism or by taxonom...

Corpus desk

Index EN-sex · sex · English

sex · rank #611 · 0 variants · 20 confusables

  • FREQ-CORE #611
  • LEN-MID 3 letters
  • VOW-1 1 vowel
  • CONFUS-HIGH 20 pairs
  • VAR-0 0 variants
  • BOOK-DENSE 6,566
  • PHOTO-FINISH project

Nearest frequency peer: project (-1 rank slots)

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Frequency neighbourhood for “sex”

Lower corpus rank = more everyday usage (inverted bar length for readability)

corpus weight

What this shows Bars show where “sex” sits against the nearest ranked English headwords in the FrequencyWords band, not a reprint of letter-browse containment.

Source FrequencyWords open word-frequency list As of September 3, 2026

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

sex vs so
33% similar
sex vs SI
0% similar
sex vs SS
0% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for sex
PropertyValue
Headwordsex
LanguageEnglish
Part of speechNoun
IPA/sɛks/
Letters3
Frequency rank#611
Misspellings tracked0
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “sex” sits in English frequency

Word frequency stretches from the small set of words we reach for constantly (left) out to the long tail barely used once in a while (right).sexlands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

The axis is logarithmic, with each marked tick roughly ten times rarer than the last. Same rarity band neighbours include “project” (#610), “shot” (#612), “miss” (#609). Source: FrequencyWords open word-frequency list.

Easy to mix with look-alikes

The spelling risk for sex is neighbouring look-alikes ("so", "SI", …), not just typos; it is anoun pronounced /sɛks/. Frequency #611 among 6,566 “S” headwords. 7 recorded senses keep meaning in play.

Our edit-distance generator produced no likely misspellings for sex, since its letter pattern doesn't lend itself to common typo substitutions. It also participates in 20 confusable-pair relationships, "so", "SI", "SS", and more, where similar look or sound leads writers to substitute one word for another in context.

Etymologically, the entry records: Etymology tree Proto-Indo-European *sek-der. Proto-Indo-European *séksusder. Proto-Italic *seksus Latin sexusder. Old French sexeder. Middle English sexe English sex From Middle English sexe (“sex [distinction between male and female] and gender”), from Old… The correct English form is sex, spelled S-E-X.

Definition

  1. 1
    A category into which sexually-reproducing organisms are divided on the basis of their reproductive roles in their species; the system of such categories, which can differ by organism or by taxonomic branch.
  2. 2
    Another category, especially of humans and especially based on sexuality or gender roles.
  3. 3
    The members of such a category, taken collectively.
  4. 4
    The distinction and relation between these categories, especially in humans; gender.
  5. 5
    Women; the human female gender and those who belong to it.
  6. 6
    Sexual activity, usually sexual intercourse unless preceded by a modifier.
  7. 7
    Genitalia: a penis or vagina/vulva.

Recorded use

Wiktionary examples

These source excerpts show how sex appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. The effect of the medication is dependent upon age, sex, and other factors.
  2. The right of citizens of the United States to vote shall not be denied or abridged by the United States or by any State on account of sex.

Etymology

Etymology tree Proto-Indo-European *sek-der. Proto-Indo-European *séksusder. Proto-Italic *seksus Latin sexusder. Old French sexeder. Middle English sexe English sex From Middle English sexe (“sex [distinction between male and female] and gender”), from Old French sexe (“genitals; gender”), from Latin sexus (“gender; gender traits; males or females; genitals”), from Proto-Italic *seksus, from Proto-Indo-European *séksus, from *sek- (“to cut, cut off, sever”), thus meaning "section, division" (into male and female). Usage for women influenced by Middle French le sexe (“women”) (attested in 1580). Usage for third and additional sexes calqued from French troisième sexe, referring to masculine women in 1817 and homosexuals in 1847. First used by Lord Byron and others in English in reference to Catholic clergy. Usage for sexual intercourse first attested in 1899 (in the writings of H. G. Wells).

Synonyms

This word in other languages

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "sex"?
"sex" is spelled S-E-X. The IPA pronunciation is /sɛks/.
What does "sex" mean?
As a noun, "sex" means: A category into which sexually-reproducing organisms are divided on the basis of their reproductive roles in their species; the system of such categories, which can differ by organism or by taxonom...
What words are commonly confused with "sex"?
"sex" is commonly confused with "so", "SI", "SS". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "sex"?
The IPA (International Phonetic Alphabet) transcription for "sex" is /sɛks/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "sex"?
Etymology tree Proto-Indo-European *sek-der. Proto-Indo-European *séksusder. Proto-Italic *seksus Latin sexusder. Old French sexeder. Middle English sexe English sex From Middle English sexe (“sex [distinction between male and female] and gender”)... See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Similar English words by spelling shape

Same letter count and similar misspelling depth for "sex", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 3 letters (nearest by frequency rank).

What to do next

You've looked up "sex". Here's where to go from here.

  • "sex" maps to 20 confusable pairs in this vintage; the highest-scored is "so". View pair
  • Usage frequency rank #611 among English headwords in this corpus. Corpus statistics
  • Browse more English words in the "S" letter cohort. S–Z browse
  • PlainSpell rotates a curated Word of the Day from the English corpus, a passive way to discover vocabulary. Word of the Day

PlainSpell is a reference corpus, not spelling advice. Verify unusual forms in context.

Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list