adj. 1 deficient in strength, power, or number; fragile; easily broken or bent or defeated. 2 deficient in vigour; sickly, feeble (weak health; a weak imagination). 3 a deficient in resolution; easily led (a weak character). b (of an action or features) indicating a lack of resolution (a weak surrender; a weak chin). 4 unconvincing or logically deficient (weak evidence; a weak argument). 5 (of a mixed liquid or solution) watery, thin, dilute (weak tea). 6 (of a style etc.) not vigorous or well-knit; diffuse, slipshod. 7 (of a crew) short-handed. 8 (of a syllable etc.) unstressed. 9 Gram. in Germanic languages: a (of a verb) forming inflections by the addition of a suffix to the stem. b (of a noun or adjective) belonging to a declension in which the stem originally ended in -n (opp. STRONG adj. 22). weak ending an unstressed syllable in a normally stressed place at the end of a verse-line. the weaker sex derog. women. weak grade Gram. an unstressed ablaut-form. weak interaction Physics the weakest form of interaction between elementary particles. weak-kneed colloq. lacking resolution. weak-minded 1 mentally deficient. 2 lacking in resolution. weak-mindedness the state of being weak-minded. weak moment a time when one is unusually compliant or temptable. weak point (or spot) 1 a place where defences are assailable. 2 a flaw in an argument or character or in resistance to temptation. weakish adj.
[ ME f. ON veikr f. Gmc ]