1.
If something shoots up , it grows or increases very quickly.
Sales shot up by 9% last month...
The fair market value of the property shot up.
PHRASAL VERB : V P by/to n , V P
2.
If a drug addict shoots up , they inject a quantity of drugs into their body. ( INFORMAL )
Drug addicts shoot up in the back alleys...
We shot up heroin in the playground.
PHRASAL VERB : V P , V P n (not pron)