lax

Concise Oxford English Dictionary © 2008 Oxford University Press:
lax/laks/

▶adjective

• 1 not sufficiently strict, severe, or careful.

• 2 (of the limbs or muscles) relaxed.

• 3 Phonetics (of a speech sound, especially a vowel) pronounced with the vocal muscles relaxed. The opposite of tense1.

– derivatives
laxity noun,
laxly adverb,
laxness noun.

– origin ME: from L. laxus.