1. (a.) Weak; feeble; bedridden; as, an infirm body\; an infirm constitution.

2. (a.) Weak of mind or will; irresolute; vacillating.

3. (a.) Not solid or stable; insecure; precarious.

4. (v. t.) To weaken; to enfeeble.

Adamic abulic adrift afloat afraid ailing alternating amorphous anile backsliding cachectic capricious carnal changeable changeful cowardly crabbed crippled crumbling dangerous debilitated decrepit desultory deviable disintegrating dizzy doddered doddering doddery drained eccentric enervated enfeebled erratic erring exhausted failing faint fainthearted fallen faltering fast and loose feeble feebleminded fickle fitful fleshly flickering flighty flimsy flitting fluctuating fossilized fragile frail freakish gerontal gerontic giddy hazardous healthless ill impetuous impulsive impure in poor health inconsistent inconstant indecisive indisposed insecure insubstantial invalid invertebrate irregular irresolute irresponsible lame languishing lapsed mazy mercurial moody moribund mossbacked moth-eaten mummylike of easy virtue on the decline pale palsied papery-skinned peaked peaky peccable perilous pliable poor poorish postlapsarian precarious prodigal provisional rambling ravaged with age recidivist recidivistic reduced reduced in health restless rickety risky rotten rotten at roving run to seed run-down rusty scatterbrained senile shaky shapeless shifting shifty shriveled shuffling sick sickly slippery soft spasmodic spineless stricken in years temporary tentative ticklish timeworn tottering tottery treacherous unaccountable unangelic uncertain unchaste unclean uncontrolled undependable undisciplined unfaithworthy unfirm unfixed ungodly ungood unhealthy unpredictable unreliable unrestrained unrighteous unsaintly unsettled unsolid unsound unstable unstable as water unstaid unsteadfast unsteady unsturdy unsubstantial unsure untrustworthy unvirtuous unwell vacillating vagrant valetudinarian valetudinary variable vicissitudinary vicissitudinous virtueless volatile wandering wanton wasted wavering wavery wavy wayward weak weak-kneed weak-minded weak-willed weakened weakly whimsical wishy-washy with low resistance withered wizened wobbling wobbly