When is the term "Turbolift" first used in Star Trek?
(using real-world timing, not in-universe timing)
In Star Trek II: Wrath of Khan, after Captain Kirk presses the "stop" button for a short conversation with Lieutenant Saavik, the doors open and Dr. McCoy says:
MCCOY: Who's been holding up the damn elevator?
By the time we get to Star Trek: The Next Generation, they don't call it an "elevator" any more. Instead, they call it a "turbolift".
When did this start? What's the first occurrence of the term "turbolift"?