slackener

English

Etymology

slacken +‎ -er

Noun

slackener (plural slackeners)

1. One who slackens.
   • 1902, Anne Macdonell, Sons of Francis, page 391:

     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.

2. Part of a loom that slackens the threads.