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Showing results for toughen. Search instead for toughens.
Definitions

toughen

[tuhf-uhn] / ˈtʌf ən /
VERB
harden
Synonyms
STRONGEST
strengthen
STRONG
acclimate acclimatize anneal brutalize develop inure season temper
WEAK
climatize make difficult
Antonyms
STRONG
soften
WEAK
flex tenderize

From Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.