Source : Webster's Revised Unabridged Dictionary (1913)

So-so \So"-so`\, a. [So + so.]
   Neither very good nor very bad; middling; passable;
   tolerable; indifferent.

         In some Irish houses, where things are so-so, One
         gammon of bacon hangs up for a show.     --Goldsmith.

         He [Burns] certainly wrote some so-so verses to the
         Tree of Liberty.                         --Prof.
                                                  Wilson.

So-so \So"-so`\, adv.
   Tolerably; passably. --H. James.

Source : WordNet®

so-so
     adj : 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},
            {passable}, {so-so(p)}, {tolerable}]
     adv : in an acceptable (but not outstanding) manner; "she plays
           tennis tolerably" [syn: {acceptably}, {tolerably}]
           [ant: {unacceptably}, {unacceptably}]