zone-beat indicator

beat to arms

beat hollow

drum-beat cadence

beam / beat the opposition

beat of pointer

beat the аlarm

instantaneous vertical speed indicator / instantaneous vertical-speed indicator (IVSI)

grid zone / grid-zone

zone standard time (zone time) (ZST)

killing zone / kill zone

grid zone designation / Grid Zone Designator

grey-zone / grey zone (international relations)

hundred-per-cent zone (one-hundred-per-cent zone)

no-fire zone / no fire zone

flight restriction zone / flight restricted zone (FRZ)

air-flow indicator

artificial horizon (gyro horizon/ attitude indicator)

desiccant indicator

gyro course indicator

indicator console

indicator lamp

indicator light

indicator system

performance indicator

radiac computer-indicator

range height indicator (RHI) scope

target indicator

telltale indicator

turbine inlet temperature indicator

vertical gyro indicator

vertical scale indicator

counter indicator