Jack Harkness: Doc, what you got?

Doctor: I’ve got a sonic… Never mind.

Jack Harkness: What?

Doctor: It’s sonic, okay? Let’s leave it at that.

Jack Harkness: Disruptor? Cannon? What?

Doctor: It’s sonic, totally sonic. I am soniced up.

Jack Harkness: A sonic what?

Doctor: Screwdriver!

(Tiny bit later…)

Jack Harkness: Who has a sonic screwdriver?

Doctor: I do.

Jack Harkness: Who looks at a screwdriver and thinks, “Ooh, this could be more sonic?”

Doctor: You’ve never been bored? Never had a long night? Never had a lot of cabinets to put up?

From Doctor Who – Season 1 Episode 10: ‘The Doctor Dances’ (1×10)