Answer: boosting

AnswerCrossword Clue
BOOSTINGShoplifting, in slang
boostingBOOST, to increase (to become larger, also ENCREASE)
boostingHelp or encourage (something) to increase or improve
boostingPush from below; assist
boostingSteal, esp. by shoplifting or pickpocketing
boostingAmplify (an electrical signal)