[1] : The Collaborative International Dictionary of English v.0.48

infirm \infirm"\ i^nf~erm", a. l. infirmus: cf. f.
   infirme. see in- not, and firm, a.
   1. not firm or sound; weak; feeble; as, an infirm body; an
      infirm constitution.
      1913 webster

            a poor, infirm, weak, and despised old man. --shak.
      1913 webster

   2. weak of mind or will; irresolute; vacillating. "an infirm
      judgment." --burke.
      1913 webster

            infirm of purpose                    --shak.
      1913 webster

   3. not solid or stable; insecure; precarious.
      1913 webster

            he who fixes on false principles treads or infirm
            ground.                               --south.

   syn: debilitated; sickly; feeble; decrepit; weak; enfeebled;
        irresolute; vacillating; imbecile.
        1913 webster
see also:
in- firm 

[2] : The Collaborative International Dictionary of English v.0.48

infirm \infirm"\, v. t. l. infirmare : cf. f. infirmer.
   to weaken; to enfeeble. obs. --sir w. raleigh.
   1913 webster

[3] : WordNet (r) 2.0

infirm
     adj 1: confined to bed by illness syn: bedfast, bedridden, bedrid,
             sick-abed
     2: lacking physical strength or vitality; "a feeble old woman";
        "her body looked sapless" syn: decrepit, debile, feeble,
         sapless, weak, weakly
     3: lacking firmness of will or character or purpose; "infirm of
        purpose; give me the daggers" - shakespeare
     4: weak and feeble; "i'm feeling seedy today" syn: debilitated,
         enfeebled, seedy
see also:
bedfast bedridden bedrid sick-abed decrepit debile 
feeble sapless weak weakly debilitated 
enfeebled seedy 

[4] : Moby Thesaurus II by Grady Ward, 1.0

202 moby thesaurus words for "infirm":
   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

[5] : Bouvier's Law Dictionary, Revised 6th Ed (1856)

infirm. weak, feeble. 
     2. when a witness is infirm to an extent likely to destroy his life, or 
to prevent his attendance at the trial, his testimony de bene esge may be 
taken at any age. 1 p. will. 117; see aged witness.; going witness. 

Infirm >> I Words
Infirm, definition of term: Infirm
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