Webster's Revised Unabridged Dictionary · 1913

Lax

Lax (laks) , adjective

[Latin laxus Compare Laches, Languish, Lease, transitive verb, Leash.]

1.
Not tense, firm, or rigid; loose; slack; as, a lax bandage; lax fiber.
The flesh of that sort of fish being lax and spongy. — Ray
2.
Not strict or stringent; not exact; loose; weak; vague; equivocal.
The discipline was lax. — Macaulay
Society at that epoch was lenient, if not lax, in matters of the passions. — J. A. Symonds
The word “aternus” itself is sometimes of a lax signification. — Jortin
3.
Having a looseness of the bowels; diarrheal.

Lax , noun

A looseness; diarrhea.