(as) weak as a kitten

(as) weak as a kitten

Especially weak, feeble, and vulnerable; completely unable to defend oneself. The heart attack left me bedridden and weak as a kitten for nearly a month. Tom's always been as weak as a kitten, so we don't bother trying to roughhouse with him at all.
See also: kitten, weak
Farlex Dictionary of Idioms.

weak as a kitten

Feeble and fragile, as in After that bout with flu she was weak as a kitten. This simile has largely replaced weak as a cat, from the early 1800s.
See also: kitten, weak
The American Heritage® Dictionary of Idioms by Christine Ammer.

weak as a kitten

Feeble, defenseless. This proverbial simile goes one better than weak as a cat, dating from the early nineteenth century. Erle Stanley Gardner had “He felt as weak as a kitten” in The Case of the Drowsy Mosquito (1943). Other variations are O. Henry’s weak as a vegetarian cat (Cupid à la Carte, 1907) and weak as a newborn kitten.
See also: kitten, weak
The Dictionary of Clichés by Christine Ammer
See also:
  • kitten
  • weak as a kitten
  • weak as a baby
  • (as) weak as a baby
  • weak sister
  • weak
  • week
  • get (one's)/the knife into (someone)
  • knives
  • put/stick the knife in