From Longman Dictionary of Contemporary Englishknock somebody/something ↔ up phrasal verb informal1 MAKEto make something quickly and without using much effort Michael knocked up a shed in the back garden.2 British EnglishWAKE UP/GET UP to wake someone up by knocking on their door What time do you want me to knock you up in the morning?3 informal not politeSEX/HAVE SEX WITH to make a woman pregnant → knock→ See Verb table
Examples from the Corpus
knock up• Another who knocked them up before daylight.• Keeping in mind the penalties for knocking thought up by these sixth graders, I pull open the door and slip inside.• Letty knocked and glancing up Emily saw a slight figure with a mass of dark hair following the maid into the room.• With Young, concussions and assorted knocks are piling up like unpaid bills.• Then he knocks it up off the Road to about nine inches for a 4.• A loud determined knock draws him up sharply.• Everyone else appeared to have some sort of credit card that knocked off up to 25 percent.• She was out of control, she said, knocking back up to ten cups of coffee a day.knock-upˈknock-up noun [countable] British English DSOthe time before a tennis match officially starts when the players hit the ball to each other for practice → warm-up 