Etymology

Verb

1. To pledge, to put something at risk or on the line.
2. To guarantee or promise (to do something.)
3. To bind through legal or moral obligation (to do something, especially to marry) (usually in passive)
4. To engross or hold the attention of someone.
5. To fascinate or win over someone.
6. To employ or obtain the services of someone.
7. To reserve or arrange the use of.
8. To mesh or interlock (of machinery, especially a clutch).
9. To cause to mesh or interlock.

   Whenever I engage the clutch, the car stalls out.

10. To enter into (an activity), to participate (construed with ).
11. To keep busy or occupied.
12. To attract, to draw into conversation.
13. To enter into conflict with (an enemy).
14. To enter into battle.
15. To bring together or prepare before fighting.
16. In air defense, a fire control order used to direct or authorize units and/or weapon systems to fire on a designated target. (JP 1-02 Department of Defense Dictionary of Military and Associated Terms).
17. To bring the enemy under fire. (JP 1-02 Department of Defense Dictionary of Military and Associated Terms).

Verb

1. first-, third-person singular indicative present of engager
2. first-, third-person singular subjunctive present of engager
3. second-person singular imperative of engager