heartstopper

[ hahrt-stop-er ]
/ ˈhɑrtˌstɒp ər /

noun

something so frightening or emotionally gripping as to make one's heart seem to stop beating: We didn't crash, but it was a heartstopper.

Origin of heartstopper

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019