unsummon means to send (a summoned creature) back to its own plane of existence. Lexicurio rates it Rare gem — a strength score of 75 out of 100.
Etymology
From un- + summon.
verb
- To send (a summoned creature) back to its own plane of existence.“"I just noticed... is little Nase gone?" "She vanished a little while ago." "You mean the spell ran out." "Yes. You'd have noticed if I'd unsummoned her prematurely."”