1. отбыть ( вн. ) serve ( d. )
отбывать наказание — serve one's sentence
отбывать срок — serve time
отбывать воинскую повинность уст. — serve one's time in the army, do one's military service
2. отбыть (из; уезжать ) depart (from), leave* ( d. ); (в вн. ) leave* (for)
отбыть в Москву — leave* for Moscow