engaged

unavailable for use by anyone else or indicating unavailability; (`engaged' is a British term for a busy telephone line)

“receptionists' telephones are always engaged”

interlocked and interacting

“the gears are engaged”

having ones attention or mind or energy engaged

“deeply engaged in conversation”

reserved in advance

built against or attached to a wall

“engaged columns”

having services contracted for

“the carpenter engaged (or employed) for the job is sick”

involved in military hostilities

“the desperately engaged ships continued the fight”