The Collaborative International Dictionary of English v.0.48:

Spa \Spa\ (?; 277), n.
   A spring or mineral water; -- so called from a place of this
   name in Belgium.
   [1913 Webster]

WordNet (r) 3.0 (2006):

spa
    n 1: a health resort near a spring or at the seaside [syn:
         watering place, watering hole, spa]
    2: a fashionable hotel usually in a resort area [syn: resort
       hotel, spa]
    3: a place of business with equipment and facilities for
       exercising and improving physical fitness [syn: health spa,
       spa, health club]

Moby Thesaurus II by Grady Ward, 1.0:

40 Moby Thesaurus words for "spa":
   bagnio, balneae, balneum, bath, bathhouse, bathroom, baths,
   caldarium, casino, club, clubhouse, gambling house,
   gathering place, hangout, haunt, health resort, hot spring,
   lavatory, meeting place, mikvah, mineral spring, public baths,
   pump house, pump room, purlieu, rallying point, resort, rest room,
   sauna, springs, stamping ground, steam room, sudarium, sudatorium,
   sweat room, tepidarium, thermae, washroom, watering place,
   waters



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SPA
       Software Publishers Association (org., USA)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SPA
       Storage Pool Allocator (ZFS)