Definition of: weak

(wēk) adjective
1. Lacking in physical strength; wanting in energy, activity, or vigor; feeble; debilitated.
2. Insufficiently resisting stress; incapable of supporting weight: a weak link or bridge.
3. Lacking in strength of will or stability of character; yielding easily to temptation; pliable.
4. Ineffectual, as from deficient supply: weak artillery support.
5. Lacking in power or sonorousness: a weak voice.
6. Lacking a specified component or components in the usual or proper amount; of less than customary strength or potency: weak tea, a weak tincture.
7. Lacking the power or ability to perform properly its function: a weak heart.
8. Lacking in mental or moral strength; liable to err or fail through feebleness of conception or vacillation of judgment.
9. Showing or resulting from poor judgment or a want of discretion or firmness: a weak plan; unable to persuade or convince: a weak argument.
10. Lacking in influence or authority: a weak state.
11. Deficient in strength, durability, skill, experience, or the like.
12. Gram. In Germanic languages: a Of verbs, forming the past tense and past participle by the addition of a dental suffix to the present stem; as, English ask, asked; sight, sighted; German leben, lebte, gelebt. Some weak verbs in English show vowel change in the stem (as in leave, left), but in such cases the change is due to factors other than ablaut. Also called regular. b Of nouns and adjectives (in German and Old English), inflected in the less full manner originally restricted to stems ending in –n. Weak nouns and adjectives in Old English characteristically terminate in –a in the masculine singular (nama name) and –e in the feminine singular (tunge tongue). In German, a descriptive adjective appears in the weak form when preceded by a limiting word, such as the definite article, having strong inflection (der gute Mann). Compare STRONG (def. 28).
13. Phonet. Unstressed; unaccented, as a syllable or sound.
14. Phot. Thin; wanting in contrast: a weak negative.
15. In prosody, indicating a verse ending in which the accent falls on a word or syllable otherwise without stress.
16. Declining in price; without an active market: The wheat market is weak.
17. Wanting in impressiveness or interest: a weak play or book. See synonyms under FAINT, FRAGILE, PUSILLANIMOUS, SICKLY. ♦ Homophone: week. [<ON veikr. Akin to OE wac.]
—weak′ly adverb
—weak′ness noun
Weak may appear as a combining form in hyphemes or as the first element in two–word phrases; as in: