brother-in-law

/ˈbɹʌðɚ ɪn ˌlɔ/

//ˈbɹʌðɚ ɪn ˌlɔ// noun

"brother-in-law" is a 12-letter English headword indexed on PlainSpell.

The verdict

“brother-in-law” is uncommon English (outside the top frequency list), classed as a noun. The kind of spelling people second-guess.

Unranked
below top-frequency English
14
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - A male relative of one's generation, separated by one degree of marriage:

Corpus desk

Index EN-brother-in-law · brother-in-law · English

brother-in-law · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-MEGA 14 letters
  • VOW-4 4 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "B" thin
  • PHOTO-UNK Peer pending

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.

Key facts for brother-in-law
PropertyValue
Headwordbrother-in-law
LanguageEnglish
Part of speechNoun
IPA/ˈbɹʌðɚ ɪn ˌlɔ/
Letters14
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “brother-in-law” in English

brother-in-lawfalls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

brother-in-law is uncommon English outside the top frequency list, classed as anoun, transcribed /ˈbɹʌðɚ ɪn ˌlɔ/. Rarity is why readers land here mid-draft. 4 senses are on record.

Our edit-distance generator produced no likely misspellings for brother-in-law, suggesting the orthography follows predictable English patterns. We don't track a confusable pairing for this entry, suggesting its spelling stands apart enough that readers rarely confuse it with something else.

Etymologically, the entry records: From Middle English brother-in-lawe; equivalent to brother + -in-law. The correct English form is brother-in-law, spelled B-R-O-T-H-E-R---I-N---L-A-W.

Definition

  1. 1
    A male relative of one's generation, separated by one degree of marriage:
  2. 2
    A male relative of one's generation, separated by one degree of marriage:
  3. 3
    Co-brother-in-law: A male relative of one's generation, separated by two degrees of marriage:
  4. 4
    Co-brother-in-law: A male relative of one's generation, separated by two degrees of marriage:

Recorded use

Wiktionary examples

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

  1. The US Securities and Exchange Commission has closed its insider trading investigation into stock trades made by then-Sen. Richard Burr and his brother-in-law at the outset of the pandemic, the former senator announced Friday.
  2. He was appalled by trench conditions and the prolongation of the war, a disillusionment further encouraged by the Easter rising, in which his brother-in-law, Francis Sheehy-Skeffington (qv), was murdered by a deranged Anglo–Irish officer, J. C. Bowen-Colthurst (qv).

Etymology

From Middle English brother-in-lawe; equivalent to brother + -in-law.

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). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "brother-in-law"?
"brother-in-law" is spelled B-R-O-T-H-E-R---I-N---L-A-W. The IPA pronunciation is /ˈbɹʌðɚ ɪn ˌlɔ/.
What does "brother-in-law" mean?
As a noun, "brother-in-law" means: A male relative of one's generation, separated by one degree of marriage:
How do you pronounce "brother-in-law"?
The IPA (International Phonetic Alphabet) transcription for "brother-in-law" is /ˈbɹʌðɚ ɪn ˌlɔ/. 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 "brother-in-law"?
From Middle English brother-in-lawe; equivalent to brother + -in-law. 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.

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

Source: FrequencyWords open word-frequency list