strengthen

/ˈstɹɛŋ(k)θən/

//ˈstɹɛŋ(k)θən// verb

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

"strengthen" is a 10-letter English headword indexed on PlainSpell.

The verdict

“strengthen” is a regularly-used English word, ranked #6,743 in English word frequency and used as a verb.

#6,743
frequency rank, English
10
letters
17
tracked misspellings
3
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - To make strong or stronger; to add strength to; to increase the strength of; to fortify.

Visual similarity to commonly confused words

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

strengthen vs strengths
80% similar
strengthen vs strengthened
83% similar
strengthen vs strength
80% similar

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

Key facts for strengthen
PropertyValue
Headwordstrengthen
LanguageEnglish
Part of speechVerb
IPA/ˈstɹɛŋ(k)θən/
Letters10
Frequency rank#6,743
Misspellings tracked17
Confusable pairs3
SourceWiktionary (kaikki.org)

Where “strengthen” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). strengthen lands here:

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

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for strengthen is 10 letters long, classified as a verb, and transcribed in the International Phonetic Alphabet as /ˈstɹɛŋ(k)θən/. Corpus data places it at rank #6,743 in overall English word frequency, indicating it appears regularly in written and spoken text. Wiktionary records 6 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 17 likely wrong-spelling variants for strengthen, with forms such as "srtengthen", "sstrengthen", and "sterngthen". Each of these forms differs from the correct spelling by one small edit: a doubled letter, a dropped silent letter, or a substituted vowel. It also participates in 3 confusable-pair relationships, "strengths", "strengthened", "strength", since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: From rare Middle English strengthenen (14th c.), from earlier strengthen (12th c.), where -en is the infinitive ending. Probably the original form was reinterpreted as strength + -en around the time when the infinitive ending was being apocopated in late Mi… The correct English form is strengthen, spelled S-T-R-E-N-G-T-H-E-N.

Definition

  1. 1
    To make strong or stronger; to add strength to; to increase the strength of; to fortify.
  2. 2
    To empower; to give moral strength to; to encourage; to enhearten.
  3. 3
    To augment; to improve; to intensify.
  4. 4
    To reinforce, to add to, to support (someone or something)
  5. 5
    To substantiate; to corroborate (a belief, argument, etc.)
  6. 6
    To grow strong or stronger.

Etymology

From rare Middle English strengthenen (14th c.), from earlier strengthen (12th c.), where -en is the infinitive ending. Probably the original form was reinterpreted as strength + -en around the time when the infinitive ending was being apocopated in late Middle English.

Synonyms

annealbracebuild upconfirmenstrengthenfortifyhardenintendindurateinvigoratemunitenervenerve upreinforceroboratesteelstrengthstrengthenthicken

Antonyms

weakenatrophydebilitateenervateenfeeble

This word in other languages

fortalecer(Español)renforcer(Français)verstärken(Deutsch)fortalecer(Português)

Common misspellings

Also misspelled as: srtengthen,sstrengthen,sterngthen,stregnthen,strenggthen,strenghten,strengtehn,strengthenn,strengthhen,strengthne,strengtthen,strenngthen,strentghen,strnegthen,strrengthen,sttrengthen,tsrengthen

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of strengthen - counted as single-character edits (an insertion, a deletion, or a substituted letter). The larger the bar, the easier the typo is to spot; one-edit slips are the ones that sneak past readers.

srtengthen2sstrengthen1sterngthen2stregnthen2strenggthen1strenghten2strengtehn2strengthenn1
Edit distance from "strengthen"

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 "strengthen"?
"strengthen" is spelled S-T-R-E-N-G-T-H-E-N. The IPA pronunciation is /ˈstɹɛŋ(k)θən/.
What does "strengthen" mean?
As a verb, "strengthen" means: To make strong or stronger; to add strength to; to increase the strength of; to fortify.
What words are commonly confused with "strengthen"?
"strengthen" is commonly confused with "strengths", "strengthened", "strength". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "strengthen"?
The IPA (International Phonetic Alphabet) transcription for "strengthen" is /ˈstɹɛŋ(k)θən/. 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 "strengthen"?
From rare Middle English strengthenen (14th c.), from earlier strengthen (12th c.), where -en is the infinitive ending. Probably the original form was reinterpreted as strength + -en around the time when the infinitive ending was being apocopated ... 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.

Using “strengthen”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is S-T-R-E-N-G-T-H-E-N - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈstɹɛŋ(k)θən/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “strengths” - see the side-by-side comparison. strengthen vs strengths
  • 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.

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list