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deceleration

[dee-sel-uh-rey-shuhn] / diˌsɛl əˈreɪ ʃən /
NOUN
slowdown
Synonyms
STRONGEST
decline delay downtrend downturn drop drop-off falloff slackening stagnation strike
STRONG
arrest freeze inactivity retardation slack stoppage
WEAK
slow-up
Antonyms
STRONGEST
increase rise
WEAK
breakthrough

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