The Collaborative International Dictionary of English v.0.48:

Salvo \Sal"vo\, n.; pl. Salvos. [L. salvo jure, literally, the
   right being reserved. See Safe.]
   An exception; a reservation; an excuse.
   [1913 Webster]

         They admit many salvos, cautions, and reservations.
                                                  --Eikon
                                                  Basilike.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Salvo \Sal"vo\, n. [F. salve a discharge of heavy cannon, a
   volley, L. salve hail, imperat. of salvere to be well, akin
   to salvus well. See Safe.]
   1. (Mil.) A concentrated fire from pieces of artillery, as in
      endeavoring to make a break in a fortification; a volley.
      [1913 Webster]

   2. A salute paid by a simultaneous, or nearly simultaneous,
      firing of a number of cannon.
      [1913 Webster]

WordNet (r) 3.0 (2006):

salvo
    n 1: an outburst resembling the discharge of firearms or the
         release of bombs
    2: rapid simultaneous discharge of firearms; "our fusillade from
       the left flank caught them by surprise" [syn: fusillade,
       salvo, volley, burst]
    3: a sudden outburst of cheers; "there was a salvo of approval"

Moby Thesaurus II by Grady Ward, 1.0:

96 Moby Thesaurus words for "salvo":
   allowance, anniversaries, antiaircraft barrage, appreciation, bang,
   bark, barrage, blast, bombardment, bowshot, box barrage, broadside,
   bullet, burst, cannon, cannonade, cannonry, celebrating,
   celebration, ceremony, cession, circumscription, commemoration,
   concession, crack, creeping barrage, detonation, discharge,
   dressing ship, drumfire, ejection, emergency barrage, enfilade,
   exception, exemption, explosion, extenuating circumstances,
   fanfare, fanfaronade, festivity, flourish of trumpets, fulmination,
   fusillade, grain of salt, grant, gun, gunfire, gunshot, hail,
   hedge, hedging, holiday, jubilee, limitation, marking the occasion,
   memorialization, memory, mental reservation, modification,
   mortar barrage, normal barrage, observance, ovation, pop, potshot,
   qualification, rejoicing, religious rites, remembrance,
   reservation, restriction, revel, rite, ritual observance, salute,
   shot, shower, solemn observance, solemnization, special case,
   special treatment, specialness, specification, spray,
   standing barrage, stoneshot, storm, tattoo, testimonial,
   testimonial banquet, testimonial dinner, toast, tribute, triumph,
   volley, waiver