Source : Webster's Revised Unabridged Dictionary (1913)

Loath \Loath\ (l[=o]th), a. [OE. looth, loth, AS. l[=a]?
   hostile, odious; akin to OS. l[=a][eth], G. leid, Icel.
   lei[eth]r, Sw. led, G. leiden to suffer, OHG. l[=i]dan to
   suffer, go, cf. AS. l[=i][eth]an to go, Goth. leipan, and E.
   lead to guide.]
   1. Hateful; odious; disliked. [Obs.] --Chaucer.

   2. Filled with disgust or aversion; averse; unwilling;
      reluctant; as, loath to part.

            Full loth were him to curse for his tithes.
                                                  --Chaucer.

            Why, then, though loath, yet must I be content.
                                                  --Shak.

Source : WordNet®

loath
     adj 1: unwillingness to do something contrary to your custom; "a
            reluctant smile"; "loath to admit a mistake";
            "unwilling to face facts" [syn: {loth}, {reluctant}]
     2: (usually followed by `to') strongly opposed; "antipathetic
        to new ideas"; "averse to taking risks"; "loath to go on
        such short notice"; "clearly indisposed to grant their
        request" [syn: {antipathetic}, {antipathetical}, {averse(p)},
         {indisposed(p)}, {loath(p)}, {loth(p)}]