Source : Webster's Revised Unabridged Dictionary (1913)

Relax \Re*lax"\ (r?-l?ks"), v. t. [imp. & p. p. {Relaxed}
   (-l?kst"); p. pr. & vb. n. {Relaxing}.] [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 rigorous; to abate the stringency
      of; to remit in respect to strenuousness, earnestness, or
      effort; as, to relax discipline; to relax one's attention
      or endeavors.

            The statute of mortmain was at several times relaxed
            by the legislature.                   --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.

   Syn: To slacken; loosen; loose; remit; abate; mitigate; ease;
        unbend; divert.

Relax \Re*lax"\, n.
   Relaxation. [Obs.] --Feltham.

Relax \Re**lax"\, a.
   Relaxed; lax; hence, remiss; careless.

Relax \Re*lax"\, 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.

Source : WordNet®

relax
     v 1: become less tense, rest, or take one's ease; "He relaxed in
          the hot tub"; "Let's all relax after a hard day's work"
          [syn: {loosen up}, {unbend}, {unwind}, {decompress}, {slow
          down}] [ant: {tense}]
     2: make less tight; "relax the tension on the rope" [syn: {unbend}]
     3: become loose or looser or less tight; "The noose loosened";
        "the rope relaxed" [syn: {loosen}, {loose}] [ant: {stiffen}]
     4: cause to feel relaxed; "A hot bath always relaxes me" [syn:
        {unstrain}, {unlax}, {loosen up}, {unwind}, {make relaxed}]
        [ant: {tense}, {tense}]
     5: become less tense, less formal, or less restrained, and
        assume a friendlier manner; "our new colleague relaxed
        when he saw that we were a friendly group" [syn: {loosen
        up}]
     6: make less severe or strict; "The government relaxed the
        curfew after most of the rebels were caught" [syn: {loosen}]
     7: become less severe or strict; "The rules relaxed after the
        new director arrived" [syn: {loosen}]
     8: make less active or fast; "He slackened his pace as he got
        tired"; "Don't relax your efforts now" [syn: {slack}, {slacken},
         {slack up}]