adj. 1
Lacking in force (usually strength) or ability.
The child was too weak to move the boulder.
adj. 2
Dilute, lacking in taste or potency.
We were served stale bread and weak tea.
adj. 3
Unable to sustain a great weight, pressure, or strain.
a weak timber; a weak rope
adj. 4
Limp, soft.

Related words

Word family: weaken weakfish weak-headed weakie weakling weakly weak-minded weakness
Phrases: weak sister weak point weak force weak interaction weak artificial intelligence weak atheist weak nuclear force weak nuclear interaction
Is a kind of: lacking

From weakest to strongest

From the opposite of weak, on the left, to its strongest synonyms, on the right.

Use in printed books, per decade from 1850 to 2019.

3 letters: low¹, lax¹
4 letters: poor¹, thin¹, lame¹, puny²
5 letters: light¹, vague¹, faint¹, slack¹, frail¹, washy²
6 letters: stupid², feeble², weakly², watery³, dilute², flimsy², sickly², anemic³, flabby², infirm²
7 letters: diluted³, anaemic
8 letters: delicate³, unstable³, weakened², fallible³
9 letters: exhausted³, powerless³, imperfect³, illogical⁴, tasteless², enfeebled³
10 letters: vulnerable⁴
11 letters: ineffective⁴, ineffectual⁵, debilitated⁵
12 letters: inconclusive⁴
13 letters: untrustworthy⁴, insubstantial⁴, unsubstantial

The small number after each word is its number of syllables (puny² = 2 syllables).