An Etymological Dictionary of Astronomy and Astrophysics

1a) Of, pertaining to, or suited for carrying out plans, duties, etc.

1b) Pertaining to or charged with the execution of laws and policies or the administration of public affairs.

2a) A person or group of persons having administrative or supervisory authority in an organization.

2b) The person or persons in whom the supreme executive power of a government is vested (Dictionary.com).

See also: → execute; → -ive.