subcarrier

or sub-car·ri·er

[ suhb-kar-ee-er ]
/ sʌbˈkær i ər /

noun Radio.

a carrier wave used to modify or modulate another carrier wave.

British Dictionary definitions for subcarrier

subcarrier
/ (ˈsʌbˌkærɪə) /

noun

a subsidiary carrier wave that is modulated with information and applied as modulation to a main carrier wave that is already modulated with other information