usage: lacking bodily or muscular strength or vitality; "a feeble old woman"; "her body looked sapless"
8. weak, regular (vs. irregular)
usage: (used of verbs) having standard (or regular) inflection
9. weak, powerless (vs. powerful)
usage: not having authority, political strength, or governing power; "a weak president"
10. faint, weak, perceptible (vs. imperceptible)
usage: deficient in magnitude; barely perceptible; lacking clarity or brightness or loudness etc; "a faint outline"; "the wan sun cast faint shadows"; "the faint light of a distant candle"; "weak colors"; "a faint hissing sound"; "a faint aroma"; "a weak pulse"
11. weak, fallible (vs. infallible)
usage: likely to fail under stress or pressure; "the weak link in the chain"
12. weak, stupid (vs. smart)
usage: deficient in intelligence or mental power; "a weak mind"