(uncountable) The condition of being weak. / (countable) An inadequate quality; fault / (countable) A special fondness or desire.

plural of weakness / plural of weaknesse

Lacking in force (usually strength) or ability. / Unable to sustain a great weight, pressure, or strain.

Obsolete spelling of weak

describing the weak nuclear force

(figuratively) Lacking will power or strength of character; timid. / (literally) Used other than figuratively or idiomatically: see weak, kneed.

(intransitive, idiomatic, informal) To fail to accomplish an accomplishable task or to make an attempt at less than maximum effort; to "half-ass" or "fake the funk".

Foolish or ignorant. / weak-willed; easily swayed or corrupted. / Needy or fearful; characterized by weakness. / mentally deficient

easily swayed / irresolute, indecisive

(grammar) The declension pattern of a weak noun.