Etymology 1

From salvo, a (loose) ablative of salvus, the past participle of salvere 'to save, reserve', either from salvo jure literally 'the right being reserved', or from salvo errore et omissone 'reserving error and omission'.

Noun

1. An exception; a reservation; an excuse.

   They admit many salvos, cautions, and reservations. --Eilon Basilike.

   2006 MetaFilter community weblog Britannica's issued a salvo against Nature's famous "Wikipedia and the EB are comparably error-strewn" analysis.

Etymology 2

A 1719 alteration of salva (1591) "simultaneous discharge of guns," from salva "salute, volley" (cf. , also from Italain), from , imperative of salvere: "be in good health!," the usual Roman greeting, regarded as imperative of salvere "to be in good health," but prop. voc. of salvus "healthy"

Noun

1. A concentrated fire from pieces of artillery, as in endeavoring to make a break in a fortification; a volley.
2. By extension, any volley, as in an argument or debate.
3. A salute paid by a simultaneous, or nearly simultaneous, firing of a number of cannon.