Deeply or seriously thoughtful.
Broody; incubating eggs by sitting on them.
A spell of brooding; the time when someone broods.
Effectual or important.
Functional, in working order.
Having the power of acting; hence, exerting force, physical or moral; active in the production of effects.
Producing the appropriate or designed effect; efficacious.
Based upon, or consisting of, a surgical operation or operations.
An employee or other worker with some particular function or skill.
A spy, secret agent, or detective.
A participant in an operation.