Antonyms of verb loosen

2 of 7 senses of loosen

Sense 1
loosen, loose -- (make loose or looser; "loosen the tension on a rope")
       Antonym of stiffen (Sense 2)
      => stiffen -- (make stiff or stiffer; "Stiffen the cream by adding gelatine")

Sense 7
loosen, relax, loose -- (become loose or looser or less tight; "The noose loosened"; "the rope relaxed")
       Antonym of stiffen (Sense 1)
      => stiffen -- (become stiff or stiffer; "He stiffened when he saw his boss enter the room")

Synonyms/Hypernyms (Ordered by Estimated Frequency) of verb loosen

7 senses of loosen

Sense 1
loosen, loose -- (make loose or looser; "loosen the tension on a rope")
       => change, alter, modify -- (cause to change; make different; cause a transformation; "The advent of the automobile may have altered the growth pattern of the city"; "The discussion has changed my thinking about the issue")

Sense 2
relax, loosen -- (make less severe or strict; "The government relaxed the curfew after most of the rebels were caught")
       => change, alter, modify -- (cause to change; make different; cause a transformation; "The advent of the automobile may have altered the growth pattern of the city"; "The discussion has changed my thinking about the issue")

Sense 3
relax, loosen -- (become less severe or strict; "The rules relaxed after the new director arrived")
       => change -- (undergo a change; become different in essence; losing one's or its original nature; "She changed completely as she grew older"; "The weather changed last night")

Sense 4
tease, tease apart, loosen -- (disentangle and raise the fibers of; "tease wool")
       => disentangle, unsnarl, straighten out -- (extricate from entanglement; "Can you disentangle the cord?")

Sense 5
untie, undo, loosen -- (cause to become loose; "undo the shoelace"; "untie the knot"; "loosen the necktie")
       => change, alter, modify -- (cause to change; make different; cause a transformation; "The advent of the automobile may have altered the growth pattern of the city"; "The discussion has changed my thinking about the issue")

Sense 6
loosen -- (make less dense; "loosen the soil")
       => change, alter, modify -- (cause to change; make different; cause a transformation; "The advent of the automobile may have altered the growth pattern of the city"; "The discussion has changed my thinking about the issue")

Sense 7
loosen, relax, loose -- (become loose or looser or less tight; "The noose loosened"; "the rope relaxed")
       => weaken -- (become weaker; "The prisoner's resistance weakened after seven days")