Other forms: loosened, loosening, loosens
To loosen is to make something less tight. Loosen a screw, loosen your tie, loosen the soil.
It covers screws, laces, collars and soil, and in every case it means reducing tension rather than removing the thing. Loosen up means to relax, of muscles before exercise or of a person who is being stiff. Figuratively, rules and restrictions are loosened: loosen the rules, loosen its grip. Note loosen and lose, which sound related and are not; and that the opposite is tighten.
1verbloosenTo make something less tight.
“He loosened his tie as soon as the meeting ended.”
2verbrelaxTo relax, of muscles or a person.
“A hot bath helps your muscles loosen after a long run.”
loosen is a slackening.
Proto-Indo-European
*lewh₁-
Old Norse
lauss
Middle English
loos
English
loose
English, today
loosen
From loose + -en. loose comes from Middle English loos, from Old Norse lauss. From Middle English loos, los, lous, from Old Norse lauss, from Proto-Germanic lausaz, whence also -less, leasing; from Proto-Indo-European lewh₁- (“to untie, set free, separate”), whence also lyo-, -lysis, via Ancient Greek.
Etymology from Wiktionary, CC BY-SA