/ ˈsælvəʊ; NAmE -voʊ/ noun
( pl. -os or -oes ) the act of firing several guns or dropping several bombs, etc. at the same time; a sudden attack :
The first salvo exploded a short distance away.
( figurative )
The newspaper article was the opening salvo in what proved to be a long battle.
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WORD ORIGIN
late 16th cent. (earlier as salve ): from French salve , Italian salva salutation.