ADJECTIVE (3)

1. ready for service or able to give long service;
- Example: "serviceable equipment"
- Example: "heavy serviceable fabrics"

2. capable of being put to good use;
- Example: "a serviceable kitchen gadget"

3. intended or able to serve a purpose without elaboration;
- Example: "serviceable low-heeled shoes";

The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

            I know thee well, a serviceable villain. --Shak.
      [1913 Webster]

   2. Prepared for rendering service; capable of, or fit for,
      the performance of duty; hence, active; diligent.
      [1913 Webster]

            Courteous he was, lowly, and servysable. --Chaucer.
      [1913 Webster]

            Bright-hearnessed angels sit in order serviceable.
                                                  --Milton.
      [1913 Webster]

            Seeing her so sweet and serviceable.  --Tennnyson.
      [1913 Webster] -- Serv"ice*a*ble*ness, n. --
      Serv"ice*a*bly, adv.
      [1913 Webster]

WordNet (r) 3.0 (2006):

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