Source : Webster's Revised Unabridged Dictionary (1913)

Serviceable \Serv"ice*a*ble\, a.
   1. Doing service; promoting happiness, interest, advantage,
      or any good; useful to any end; adapted to any good end
      use; beneficial; advantageous. ``Serviceable to religion
      and learning''. --Atterbury. ``Serviceable tools.''
      --Macaulay.

            I know thee well, a serviceable villain. --Shak.

   2. Prepared for rendering service; capable of, or fit for,
      the performance of duty; hence, active; diligent.

            Courteous he was, lowly, and servysable. --Chaucer.

            Bright-hearnessed angels sit in order serviceable.
                                                  --Milton.

            Seeing her so sweet and serviceable.  --Tennnyson.
      -- {Serv"ice*a*ble*ness}, n. -- {Serv"ice*a*bly}, adv.

Source : WordNet®

serviceable
     adj 1: ready for service or able to give long service; "serviceable
            equipment"; "heavy serviceable fabrics" [ant: {unserviceable}]
     2: having a beneficial use; "a serviceable kitchen gadget"
     3: intended or able to serve a purpose without elaboration;
        "serviceable low-heeled shoes";