Thesaurus.com
Dictionary.com
Definitions

rein

[reyn] / reɪn /
NOUN
restraint, control
Synonyms
STRONGEST
curb
STRONG
bit brake bridle check deterrent governor halter harness hold line restriction strap
Antonyms
STRONG
release
VERB
restrain, control
Synonyms
STRONGEST
curb repress restrict suppress
STRONG
bridle check collect compose cool halt hold limit smother
WEAK
hold back simmer down slow down
Antonyms
STRONGEST
encourage let go release
STRONG
continue disperse scatter
WEAK
free

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