releaser

re.leas.er

n.（名词）
One that releases:
释放者：
例句：
a releaser of shipments; a releaser of prisoners.
货物分发者，囚犯释放者

Zoology A stimulus that releases a specific behavior pattern in an animal.
【动物学】 释放刺激：使动物产生一种特定的行为方式的刺激物