back up

back-to-back circuit

back-to-back connection

back-to-back radio stations

back-to-back relay

back-up fire control

back-up system

cut back co-operation

I read back

play back kit

pull back

push back

read back

reverse engineering ( back- wards engineering)

Camel-back water pouch

Field Pack, Air Support Back

back brief / backbrief

peel back

back on the block

back-up circuit breaker

armor back plate

back bearing housing

back blow

back contact

back cushion

back fork

back gun

back impact

back kick

back lamp

back lash

back of periscope

back of the blade