Webster's Revised Unabridged Dictionary · 1913

Infirm

Infirm (in*fẽrm") , adjective

[Latin infirmus: compare French infirme. See In- not, and Firm, a.]

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

Infirm , transitive verb

[Latin infirmare: compare French infirmer.]

To weaken; to enfeeble. [Obsolete] — Sir W. Raleigh