decrepit

Adjective

Synonyms: creaky derelict flea-bitten run-down woebegone debile feeble infirm rickety sapless weak weakly

WordNet 3.0

Adjective (2)

worn and broken down by hard use“a creaky shack”“a decrepit bus...its seats held together with friction tape”“a flea-bitten sofa”“a run-down neighborhood”“a woebegone old shack”Synonyms: creaky derelict flea-bitten run-down woebegone
lacking bodily or muscular strength or vitality“a feeble old woman”“her body looked sapless”Synonyms: debile feeble infirm rickety sapless weak weakly

Webster's Dictionary (GCIDE)

Decrepit \De*crep"it\, a. [L. decrepitus, perhaps orig., noised out, noiseless, applied to old people, who creep about quietly; de- + crepare to make a noise, rattle: cf. F. d['e]cr['e]pit. See Crepitate.] Broken down with age; wasted and enfeebled by the infirmities of old age; feeble; worn out. "Beggary or decrepit age." --Milton. [1913 Webster]

Already decrepit with premature old age. --Motley. [1913 Webster]

Note: Sometimes incorrectly written decrepid. [1913 Webster]