防 - ward off, defend, protect

air defense; air defence

security camera

fire engine; fire truck

soundproofing

waterproofing; making watertight

breakwater; mole

erosion control

fire station

fire prevention; fire control; fireproofing

communicable disease control (e.g. by quarantine, disinfection, etc.); prevention of epidemics

offense and defense; offence and defence

national defence; national defense