Armada \Ar*ma"da\ ([aum]r*m[=a]"d[.a] or [aum]r*m[aum]"d[.a]), n. [Sp. armada, L. as if armata (sc. classic fleet), fr. armatus, p. p. of armare. See Arm, v. t. Army.]

A fleet of armed ships; a squadron. Specifically, the Spanish fleet which was sent to assail England, a. d. 1558.

Source: Webster's Revised Unabridged Dictionary (1913)