Relax (r-lks), v. t. [imp. & p. p. Relaxed (-lkst); p. pr. & vb. n. Relaxing.]
Etymology: [L. relaxare; pref. re- re- + laxare to loose, to slacken, from laxus loose. See Lax, and cf. Relay, n., Release.]
1. To make lax or loose; to make less close, firm, rigid, tense, or the like; to slacken; to loosen; to open; as, to relax a rope or cord; to relax the muscles or sinews. Horror . . . all his joints relaxed. Milton. Nor served it to relax their serried files. Milton.
2. To make less severe or rogorous; to abate the stringency of; to remit in respect to strenuousness, esrnestness, or effort; as, to relax discipline; to relax one's attention or endeavors. The stature of mortmain was at several times relaxed by the legilature. Swift.
3. Hence, to relieve from attention or effort; to ease; to recreate; to divert; as, amusement relaxes the mind.
4. To relieve from constipation; to loosen; to open; as, an aperient relaxes the bowels.
1 more senses
Syn. -- To slacken; loosen; loose; remit; abate; mitigate; ease; unbend; divert.
3 other Webster entries under this spelling
Relax, v. i.
1. To become lax, weak, or loose; as, to let one's grasp relax. His knees relax with toil. Pope.
2. To abate in severity; to become less rigorous. In others she relaxed again, And governed with a looser rein. Prior.
3. To remit attention or effort; to become less diligent; to unbend; as, to relax in study.
Relax, n.
Relaxation. [Obs.] Feltham.
Relax, a.
Relaxed; lax; hence, remiss; careless.
Shades of meaning
Fernald lists relax only as an antonym, under tire.
He lists it without comment; the entries above explain its neighbors.