哨

(preliminary) skirmish

patrol (with ships or aircraft)

outpost

general outpost

scouting line

outpost

general outpost line

outpost duty

keeping watch

combat outpost

observation post

sentry post

patrol plane

maritime patrol aircraft

sentry

Civil Air Patrol

sentry

outpost cavalry

antisubmarine patrol plane

sentry box

patrol boat

military patrol boat

Mitella stylosa (species of miterwort)

shawm-like instrument played by street vendors (sometimes referred to as a flute)