able to function or be used; functional

How soon will the new factory be operational?

Military .

of, pertaining to, or involved in military operations.

on active service or combat duty

All units of the command are operational.

of or pertaining to operations or an operation.

adjective

fit , in service , in working order , operative , practicable , practical , prepared , ready , serviceable , usable , useful , viable , workable , working