Synonyms of strengthen

strengthen

verb

ˈstreŋ(k)-thən 

1

as in to harden

to increase the ability of (as a muscle) to exert physical force

lifting weights every day will eventually strengthen your muscles

the army makes new recruits run for miles in order to strengthen them

Synonyms & Similar Words

• harden
• fortify
• toughen
• energize
• temper
• beef (up)
• invigorate
• vitalize
• tone (up)
• anneal
• firm (up)
• restrengthen

Antonyms & Near Antonyms

• weaken
• hurt
• impair
• cripple
• paralyze
• injure
• harm
• damage
• debilitate
• enfeeble
• undermine
• enervate
• incapacitate
• wear out
• break down
• undercut
• sap

2

as in to fortify

to make able to withstand physical hardship, strain, or exposure

required weeks of physical therapy to strengthen his arm enough to pitch for the team again

Synonyms & Similar Words

• fortify
• harden
• adjust
• bolster
• reinforce
• toughen
• inure
• steel
• adapt
• brace
• season
• boost
• support
• invigorate
• indurate
• vitalize
• enforce
• acclimate
• acclimatize
• temper
• immunize
• buttress
• anneal
• condition
• accustom
• train
• break in
• prop (up)
• habituate
• naturalize
• forearm
• limber (up)

Antonyms & Near Antonyms

• soften
• weaken
• exhaust
• emasculate
• sap
• cripple
• hamstring
• incapacitate
• sensitize
• enfeeble
• enervate
• debilitate

3

as in to enhance

to make markedly greater in measure or degree

encouraged the boarding school students to strengthen their ties with the community by doing public service

Synonyms & Similar Words

• enhance
• intensify
• deepen
• heighten
• consolidate
• reinforce
• broaden
• boost
• sharpen
• amplify
• expand
• redouble
• accentuate
• step up
• augment
• emphasize
• magnify
• extend
• lengthen
• beef (up)
• enforce
• accelerate
• maximize
• supplement
• enlarge
• amp (up)
• hasten
• quicken
• point (up)
• enliven
• restrengthen
• exacerbate
• stress
• aggravate
• jazz (up)

Antonyms & Near Antonyms

• reduce
• weaken
• decrease
• diminish
• moderate
• tone (down)
• lessen
• abate
• subdue
• recede
• alleviate
• subside
• lighten
• ease
• let up (on)
• wane
• dwindle
• taper (off)

4

as in to brace

to prepare (oneself) mentally or emotionally

strengthened herself for the moment she'd have to tell her friend that she had lost the borrowed necklace

Synonyms & Similar Words

• fortify
• brace
• ready
• nerve
• steel
• reinforce
• bolster
• enforce
• forearm
• poise
• psych (up)
• arm
• sustain
• encourage
• inure
• harden
• comfort
• buttress
• inspire
• toughen
• boost
• support
• season
• rouse
• embolden
• stir
• rally
• prop (up)
• hearten
• buoy (up)
• cheer (up)

Antonyms & Near Antonyms

• shake
• discourage
• undermine
• demoralize
• weaken
• daunt
• unnerve
• soften
• dishearten
• undercut
• debilitate
• psych (out)
• dispirit
• enfeeble
• sap
• tire
• prostrate
• enervate

5

as in to stiffen

to make more harsh, uncompromising, or severe

a bill was introduced to strengthen punishments for hate crimes

Synonyms & Similar Words

• stiffen
• toughen
• harden
• harshen

Antonyms & Near Antonyms

• ease
• lessen
• soften
• ameliorate
• moderate

Example Sentences

Recent Examples of strengthen

Its amino-acid complex helps smooth and strengthen strands from the inside out, while amaranth extract reinforces fragile hair and baobab extract helps improve elasticity and bounce. — Christa Joanna Lee, Allure, 7 Oct. 2026

Forecasters alert of a hurricane watch and a storm surge watch issued for portions of the northern gulf coast for strengthening isaias. — Miami Herald Hurricane Bot, Miami Herald, 7 Oct. 2026

Ding Shiqian, who led the Tsinghua work, said the result strengthens the case for reproducible nuclear clocks. — Aamir Khollam, Interesting Engineering, 7 Oct. 2026

The Oscar win for ‘I’m Still Here,’ the Oscar nominations of ‘The Secret Agent’ and the awards these films received at the Cannes and Venice Film Festivals have strengthened the Brazil brand around the world. — Marcelo Cajueiro, Variety, 7 Oct. 2026