loosen
verb
make loose or looser
“loosen the tension on a rope”
SynonymslooseOppositesstiffenmake less severe or strict
“The government relaxed the curfew after most of the rebels were caught”
Synonymsrelaxbecome less severe or strict
“The rules relaxed after the new director arrived”
Synonymsrelaxdisentangle and raise the fibers of
“tease wool”
cause to become loose
“undo the shoelace”
“untie the knot”
make less dense
“loosen the soil”
become loose or looser or less tight
“The noose loosened”
“the rope relaxed”
Oppositesstiffen
Source: WordNet 3.1, Princeton University
