DictionaryAI

strengthen

verb
STRENGK-thuhn/ˈstɹɛŋ(k)θən/

Formsstrengthens, strengthening, strengthened

6 meanings of strengthen

Practice

  1. 1
    verbtransitive
    To make someone or something stronger, or to add strength to it.

    Regular training strengthens the heart and improves circulation.

    Engineers strengthen the dam each decade to withstand higher water levels.

    Similarreinforce, fortify, toughen, bolster, harden

    Oppositeweaken, undermine, debilitate, enfeeble

    Note

    A word that survived by being misread. Middle English already had strengthen in the 12th century, when its -en was simply the infinitive ending. As that ending wore away in late Middle English, speakers probably reread the word as strength + -en, the familiar verb-forming suffix. The everyday use takes a direct object, and that object can be physical or abstract: a muscle, a wall, one's willpower, one's authority.

  2. 2
    verbintransitive
    To grow stronger, or to increase in strength.

    The economy strengthened steadily over the following quarters.

    As the currents strengthen, surfers head out to catch bigger waves.

    Similarintensify, improve, increase, grow, build

    Oppositeweaken, decline, wane, diminish

    Note

    Here the thing grows stronger by itself, with nobody doing the strengthening: a current, an economy, a feeling. It is the intransitive partner of the causative use, and it sits naturally with a phrase of time. Elizabeth Robins Pennell's Our Philadelphia (1914) describes an affection "strengthening with the years whether I will or no." The words "whether I will or no" stress that no one is acting on it.

  3. 3
    verbtransitive
    To reinforce or support someone or something by adding to it.

    International aid strengthened the region's struggling hospitals.

    Clear rules strengthen an organization and protect its members.

    Similarreinforce, support, bolster, buttress, boost

    Oppositeweaken, undermine, erode

  4. 4
    verbtransitive
    To augment, improve, or intensify something.

    The marketing campaign strengthened the brand's appeal among young buyers.

    These reforms strengthen the country's ability to respond to crises.

    Similarenhance, boost, increase, intensify, heighten

    Oppositeweaken, diminish, reduce, undermine

  5. 5
    verbtransitive
    To give someone moral strength; to encourage or embolden.

    The general's speech strengthened the weary soldiers before the final push.

    Knowing her family supported her helped strengthen her resolve.

    Similarencourage, embolden, hearten, fortify, steel

    Oppositediscourage, dishearten, demoralize, weaken

    Note

    Courage given by one person to another is an old use: the King James Bible of 1611 pairs it with encourage in "encourage him, and strengthen him." A useful construction is strengthen someone in a belief. Nat Turner's Confessions (1831) recalls parents who "strengthened me in this my first impression." Modern English more often makes the inner quality the object: strengthen her resolve, strengthen self-control.

  6. 6
    verbtransitive
    To substantiate or corroborate a belief or argument with further evidence.

    The latest findings strengthen the hypothesis that the lake is drying up.

    Independent test results strengthened the researchers' conclusions.

    Similarsupport, corroborate, substantiate, confirm, reinforce

    Oppositeundermine, weaken, contradict, refute

Practice

Can you tell the meanings of strengthen apart? Answer 4 quick questions from this page, or write your own sentence and AI will check it.

Origin

From rare Middle English strengthenen (14th century), from earlier strengthen (12th century), where -en was the infinitive ending. The form was probably reinterpreted as strength + -en around the time the infinitive ending was being dropped in late Middle English.