Isaac
/ˈaɪzək/
"isaac" is a 5-letter English headword indexed on PlainSpell.
The verdict
“Isaac” is a regularly-used English word, ranked #7,933 in English word frequency and used as a proper noun.
- #7,933
- frequency rank, English
- 5
- letters
- 6
- tracked misspellings
- 10
- confusable pairs
According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The son of Abraham and Sarah, father of Esau and Jacob, from whom the Hebrew people trace their descent.
Visual similarity to commonly confused words
How many letter changes separate each confused pair (Levenshtein distance, normalized).
Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).
| Property | Value |
|---|---|
| Headword | Isaac |
| Language | English |
| Part of speech | Proper noun |
| IPA | /ˈaɪzək/ |
| Letters | 5 |
| Frequency rank | #7,933 |
| Misspellings tracked | 6 |
| Confusable pairs | 10 |
| Source | Wiktionary (kaikki.org) |
Where “Isaac” sits in English frequency
Spelling & Dictionary Insight
The English entry for Isaac is 5 letters long, classified as a proper noun, and transcribed in the International Phonetic Alphabet as /ˈaɪzək/. Corpus data places it at rank #7,933 in overall English word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 4 distinct senses for this headword, so context determines which meaning a reader should apply.
Our generated misspelling index lists 6 likely wrong-spelling variants for Isaac, with forms such as "iasac", "isaacc", and "isac". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 10 confusable-pair relationships, "ISC", "issa", "Isla", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.
Etymologically, the entry records: From Middle English Ysaac, from Latin Isaac, from Ancient Greek Ἰσαάκ (Isaák), from Hebrew יצחק (Yiṣḥāq, literally “he laughs, he will laugh”). Explained in Genesis as referring to his mother Sarah’s laughing when she was told she would have a son at her ol… The correct English form is Isaac, spelled I-S-A-A-C.
Definition
- 1The son of Abraham and Sarah, father of Esau and Jacob, from whom the Hebrew people trace their descent.
- 2A male given name from Hebrew.
- 3A surname originating as a patronymic.
- 4A local government area in central Queensland, Australia, named after the Isaac River; in full, Isaac Region.
Etymology
From Middle English Ysaac, from Latin Isaac, from Ancient Greek Ἰσαάκ (Isaák), from Hebrew יצחק (Yiṣḥāq, literally “he laughs, he will laugh”). Explained in Genesis as referring to his mother Sarah’s laughing when she was told she would have a son at her old age. The verb is masculine, however, perhaps due to its use as a boy’s name.
This word in other languages
Common misspellings
Also misspelled as: iasac,isaacc,isac,isaca,issaac,siaac
Misspelling Pattern Breakdown
How far each generated variant is from the correct spelling of Isaac - 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.
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
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Using “Isaac”
The practical upshot for anyone who landed here from a spell-check.
- The one correct English spelling is I-S-A-A-C - every other letter order is a misspelling in standard orthography.
- Say it as /ˈaɪzək/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
- Don't mix it up with “ISC” - see the side-by-side comparison. Isaac vs ISC
- Browse more English words and confusable pairs in the same reference. English words
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.