to release or detach (somebody, esp oneself, or a part of one) from something that holds, engages, or entangles
He disengaged himself from her embrace
to remove (troops) from combat areas
said of troops or combatants: to withdraw, or retire from engagement
in fencing, to move one's sword to the other side of an opponent's sword in order to attack
disengagement noun
[French désengager, from dés- dis- + engager: see engage]