radioactivity

/ˌreɪdɪəʊakˈtɪvɪti/

//ˌreɪdɪəʊakˈtɪvɪti// noun

By · According to Wiktionary data (CC BY-SA) ·

"radioactivity" is a 13-letter English headword indexed on PlainSpell.

The verdict

“radioactivity” has 19 generated spelling variants in the English index at frequency #32,550. The variants make it a useful spelling check.

#32,550
frequency rank, English
3,094
“R” headwords
19
tracked misspellings

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.

Corpus desk

Index EN-radioactivity · radioactivity · English

radioactivity · rank #32,550 · 19 variants · 0 confusables

  • FREQ-MID #32,550
  • LEN-MEGA 13 letters
  • VOW-7 7 vowels
  • CONFUS-0 No pairs
  • VAR-HIGH 19 variants
  • BOOK-MID 3,094
  • PHOTO-FINISH Qatari

Nearest frequency peer: Qatari (-2 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.

Rank peers near misspelling magnet “radioactivity”

Same rarity band: useful when a typo lands on a peer headword

corpus weight

What this shows “radioactivity” sits among these FrequencyWords peers; misspelling depth is tracked separately in the edit-distance chart.

Source FrequencyWords open word-frequency list As of September 3, 2026
Key facts for radioactivity
PropertyValue
Headwordradioactivity
LanguageEnglish
Part of speechNoun
IPA/ˌreɪdɪəʊakˈtɪvɪti/
Letters13
Frequency rank#32,550
Misspellings tracked19
Confusable pairs0
SourceWiktionary (kaikki.org)

Frequency seat of misspelling magnet “radioactivity”

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right).radioactivitylands 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 “Qatari” (#32,548), “Raquel” (#32,552), “putter” (#32,547). Among 3,094 “R” headwords, “radioactivity” is #32,550. Source: FrequencyWords open word-frequency list.

A misspelling magnet

The generator records 19 spelling variants around radioactivity (IPA /ˌreɪdɪəʊakˈtɪvɪti/), anoun. Corpus frequency is #32,550 among 3,094 “R” headwords. Wiktionary lists 2 senses, so context still picks the gloss.

Our generated misspelling index lists 19 likely wrong-spelling variants for radioactivity, with forms such as "ardioactivity", "raddioactivity", and "radiaoctivity". Each variant is a distinct typo pattern an edit-distance generator flags, typically a doubled-consonant error, a silent-letter drop, or a vowel substitution. Our dataset records no confusable match here, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: From radioactive + -ity or radio- + activity. The correct English form is radioactivity, spelled R-A-D-I-O-A-C-T-I-V-I-T-Y.

Definition

  1. 1
    Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.
  2. 2
    The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc.

Recorded use

Wiktionary example

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

  1. Today, no one would intentionally smear radioactive materials on their face, but in 1933, the dangers of radioactivity were not yet fully understood.

Etymology

From radioactive + -ity or radio- + activity.

This word in other languages

radioactividad(Español)radioactivité(Français)Radioaktivität(Deutsch)radioatividade(Português)

Common misspellings

Also misspelled as:

  • ardioactivity
  • raddioactivity
  • radiaoctivity
  • radioacctivity
  • radioacitvity
  • radioactiivty
  • radioactivitty
  • radioactivityy
  • radioactiviyt
  • radioactivtiy
  • radioactivvity
  • radioacttivity
  • radioactviity
  • radioatcivity
  • radiocativity
  • radoiactivity
  • raidoactivity
  • rdaioactivity
  • rradioactivity

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of radioactivity - expressed in single-character edits (insert, delete, or swap one letter). Bigger bars stand out at a glance; a one-edit slip is the hardest to catch.

ardioactivity2raddioactivity1radiaoctivity2radioacctivity1radioacitvity2radioactiivty2radioactivitty1radioactivityy1
Edit distance from "radioactivity"

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 "radioactivity"?
"radioactivity" is spelled R-A-D-I-O-A-C-T-I-V-I-T-Y. The IPA pronunciation is /ˌreɪdɪəʊakˈtɪvɪti/.
What does "radioactivity" mean?
As a noun, "radioactivity" means: Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.
What are common misspellings of "radioactivity"?
Common misspellings include "ardioactivity", "raddioactivity", "radiaoctivity", "radioacctivity", "radioacitvity". The correct spelling is "radioactivity".
How do you pronounce "radioactivity"?
The IPA (International Phonetic Alphabet) transcription for "radioactivity" is /ˌreɪdɪəʊakˈtɪvɪti/. 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 "radioactivity"?
From radioactive + -ity or radio- + activity. 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 "radioactivity", not the corpus desk frequency band.

Same letter count

Frequency-ranked English headwords with 13 letters (nearest by frequency rank).

involuntarily#32,452disinterested#32,354anniversaries#32,275Aberdeenshire#32,262

Similar misspelling depth

Headwords with a similar count of attested misspellings (19 here; floor ≥5).

outstretched19 variantsstandardised19 variantsunfathomable19 variantsunprofitable19 variants

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

Source: FrequencyWords open word-frequency list