knock through (something)
1. To gain access through something by smashing a hole through it. I think we should knock through this wall to connect the living room and the dining room together. I can't believe the neighbors just knocked through the fence without asking us first.
2. To cause something to travel through something with a bump or strike. In this usage, a noun or pronoun is used between "knock" and "through." I lined up the shot and knocked the ball through croquet wickets. The kicker knocked the football effortlessly through the uprights.
3. To cause someone to smash through something. In this usage, a noun or pronoun is used between "knock" and "through." The police officer knocked the criminal through the plate glass window. He threatened to knock me through the wall if I didn't stop talking.
knock through something
to break through something. They knocked through the wall and put in a doorway. The wall had to be knocked through before we could install a doorway.