Mack truck

Noun

Mack truck (plural Mack trucks)

1. A motor vehicle produced by Mack Trucks, especially a semi-trailer.
   • their hearts were too small to pump blood to their huge bodies. It was like trying to run a Mack truck on a Volkswagen engine, and their hearts gave out.2005, Temple Grandin, Catherine Johnson, Animals in Translation: Using the Mysteries of Autism to Decode Animal Behavior, Simon and Schuster, →ISBN, pages 71–72
2. A semi-trailer of any brand.
   • Abuses committed by overly aggressive states have resulted in federal rules and paperwork motivated by the fear that without rules and record-keeping requirements, states would show up at the Treasury with a Mack truck to take away all the cash they could.2005, Gary E. Macdougal, Make a Difference: A Spectacular Breakthrough in the Fight Against Poverty, Truman Tally Books, →ISBN, page 317
3. (figuratively) Any unstoppable or enormous thing coming through.
   • I sprung out of bed and was shoved back by a Mack truck of a headache. I powered through and felt my way to the door, focusing on a sliver of grayish light glowing through the curtains.2011, Jess Lourey, October Fest, page 39
   • “I used to be a once bitten, twice shy kind of guy. Now I get hit by a Mack truck of a girl and realize my life is flashing in front of my eyes. Everything's going too fast anyway, seems easier to go jump in and go with the flow.”2018, Maggie Wells, A Ring for Rosie