1.
To roll back a change or the power of something means to gradually reduce it or end it.
Environmentalists regard these moves as the government taking advantage of the national mood to roll back protective measures...
PHRASAL VERB : V P n (not pron) , also V n P
see also rollback
2.
To roll back prices, taxes, or benefits means to reduce them. ( mainly AM )
One provision of the law was to roll back taxes to the 1975 level.
PHRASAL VERB : V P n (not pron)