The Collaborative International Dictionary of English v.0.48:

Lax \Lax\ (l[a^]ks), a. [Compar. Laxer (l[a^]ks"[~e]r);
   superl. Laxest.] [L. laxus Cf. Laches, Languish,
   Lease, v. t., Leash.]
   1. Not tense, firm, or rigid; loose; slack; as, a lax
      bandage; lax fiber.
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            The flesh of that sort of fish being lax and spongy.
                                                  --Ray.
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   2. Not strict or stringent; not exact; loose; weak; vague;
      equivocal.
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            The discipline was lax.               --Macaulay.
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            Society at that epoch was lenient, if not lax, in
            matters of the passions.              --J. A.
                                                  Symonds.
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            The word "[ae]ternus" itself is sometimes of a lax
            signification.                        --Jortin.
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   3. Having a looseness of the bowels; diarrheal.
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   Syn: Loose; slack; vague; unconfined; unrestrained;
        dissolute; licentious.
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