Infirm /(ĭn*fẽrm")/

In·firm

Infirm

a.
  1. Not firm or sound; weak; feeble; as, an infirm body; an infirm constitution.
    A poor, infirm, weak, and despised old man.
  2. Weak of mind or will; irresolute; vacillating.
    Infirm of purpose!
  3. Not solid or stable; insecure; precarious.
    He who fixes on false principles treads or infirm ground.

Infirm

v. t.
  1. To weaken; to enfeeble. [Obs.]