To serve, do service to; to be serviceable or subservient to; to serve or treat well, to benefit. Obsolete.

transitive. (The object was probably originally dative) To serve (one's turn), minister to (necessities, desires). Obsolete.

To be of service or use to; to avail.

transitive. To render useful service to (a person), to act in the interests of (a person); to work for or assist in any matter. Now somewhat rare.