slacken

1 ENTRIES FOUND:
slacken /ˈslækən/ verb
slackens; slackened; slackening
slacken
/ˈslækən/
verb
slackens; slackened; slackening
Britannica Dictionary definition of SLACKEN
1 
a  [no object] : to become slower or less active : to slow down
b  [+ object] : to make (something) slower or less active
2 
: to become less tight or to make (something) less tight : loosen
[no object]
[+ object]