空气枪

[ noun ]
an air gun in which BBs are propelled by compressed air
<noun.artifact>

airgun \air"gun`\, air gun \air" gun`\(g[u^]n`).
A kind of gun in which the elastic force of condensed air is
used to discharge the ball. The air is powerfully compressed
into a reservoir attached to the gun, by a condensing pump,
and is controlled by a valve actuated by the trigger. The
common {BB gun} is a type of air gun.