slackener means one who slackens. Lexicurio rates it Sui generis — a strength score of 87 out of 100.
Etymology
From slacken + -er.
noun
- One who slackens.“His only reference to the envoy who had denounced him is in respect of his conduct when Minister-General of the Franciscans as slackener of the Rule.”
- Part of a loom that slackens the threads.