tachy-

1. a combining form meaning “swift,” used in the formation of compound words: tachygraphy.

combining form

1. swift or acceleratedtachycardia; tachygraphy; tachylyte; tachyon; tachyphylaxis

word-forming element meaning “rapid, swift, fast,” from Latinized comb. form of Greek takhy “swift.” pref.

1. Rapid; accelerated:tachycardia.