four-boss breaker cam

чотириіскровий кулачок; (брон.) чотирьохіскровий кулачок переривника

four-cycle / four-stroke

four by four

fingertip formation / finger-four formation / four finger formation

circuit breaker / circuit-breaker

trunnion boss

boss eddy

boss vortex

air boss

ballistic offensive suppression system (BOSS)

ballistic optimizing shooting system (BOSS)

base operating supply system (BOSS)

broad ocean scoring system (BOSS)

Bureau of State Security (BOSS)

mini boss

mounting boss

piston pin boss

support boss

wrist-pin boss reinforcement

bushing boss

four-point barb

four-charge gun

four by two

four-barreled anti-aircraft gun

four-groove barrel

four-point

four-stage compressor

four-way valve

four-wheel drive

four-wheel drive truck

four-stroke cycle

four-step stand

four-stroke engine