Source : Webster's Revised Unabridged Dictionary (1913)

Passable \Pass"a*ble\, a. [Cf. F. passable.]
   1. Capable of being passed, traveled, navigated, traversed,
      penetrated, or the like; as, the roads are not passable;
      the stream is passablein boats.

            His body's a passable carcass if it be not hurt; it
            is a throughfare for steel.           --Shak.

   2. Capable of being freely circulated or disseminated;
      acceptable; generally receivable; current.

            With men as with false money -- one piece is more or
            less passable than another.           --L'Estrange.

            Could they have made this slander passable.
                                                  --Collier.

   3. Such as may be allowed to pass without serious objection;
      tolerable; admissable; moderate; mediocre.

            My version will appear a passable beauty when the
            original muse is absent.              --Dryden.

Source : WordNet®

passable
     adj 1: able to be passed or traversed or crossed; "the road is
            passable" [ant: {impassable}]
     2: about average; acceptable; "more than adequate as a
        secretary" [syn: {adequate}, {fair to middling}]
     3: neither good nor bad; "an indifferent performance"; "a
        gifted painter but an indifferent actor"; "her work at the
        office is passable"; "a so-so golfer"; "feeling only
        so-so"; "prepared a tolerable dinner"; "a tolerable
        working knowledge of French" [syn: {indifferent}, {so-so(p)},
         {tolerable}]