loosen (
http://definr.com/loosen)
v 1: make loose or looser; "loosen the tension on a rope" [syn:
loose]
[ant:
stiffen]
2: disentangle and raise the fibers of; "tease wool" [syn:
tease,
tease apart]
3: cause to become loos; "undo the shoelace"; "untie the knot";
"loosen the necktie" [syn:
untie,
undo]
4: make less dense
5: become loose or looser; "The noose loosened" [syn:
relax]
[ant:
stiffen]