1. Lacking physical strength, energy, or vigor; feeble.
2. Likely to fail under pressure, stress, or strain; lacking resistance: a weak link in a chain.
3. Lacking firmness of character or strength of will.
4. Lacking the proper strength or amount of ingredients: weak coffee.
5. Lacking the ability to function normally or fully: a weak heart.
6. Lacking aptitude or skill: a weak student; weak in math.
7. Lacking or resulting from a lack of intelligence.
8. Lacking persuasiveness; unconvincing: a weak argument.
9. Lacking authority or the power to govern.
10. Lacking potency or intensity: weak sunlight.
a. Of, relating to, or being those verbs in Germanic languages that form a past tense and past participle by means of a dental suffix, as start, started; have, had; bring, brought.
b. Of, relating to, or being the inflection of nouns or adjectives in Germanic languages with a declensional suffix that historically contained an n.
12. Unstressed or unaccented in pronunciation or poetic meter. Used of a word or syllable.
13. Designating a verse ending in which the metrical stress falls on a word or syllable that is unstressed in normal speech, such as a preposition.
14. Tending downward in price: a weak market for oil stocks.