What it means
To take the plunge means you finally stop hovering at the edge and commit to the big thing that's been making your stomach do backflips. You say it when someone quits dithering and just goes for it, like buying the place, starting the business, moving away, or popping the question.
Usage examples
"After years of talking about it, they finally took the plunge and bought the camper van."
"After years of renting they finally took the plunge and bought a little flat."
"I've been meaning to learn to dive, this summer I'm taking the plunge."
"We kept chatting about quitting London for years, then we took the plunge and moved to Bristol."
"He's been sitting on that tattoo idea since uni, so he finally took the plunge and booked the appointment."
Where it comes from
It comes from the literal image of jumping or diving into water, especially when you're stood there hesitating because it looks cold, deep, or a bit daunting. By the late 19th century, English had already started using it figuratively for finally committing to something risky or life-changing.
