
So nice of that DOCTOR
to just let you use it.
The Big Bang Theory Season 9, Episode 20

Yes, I really am a DOCTOR.
Yes, she really is my girlfriend.
The Big Bang Theory Season 9, Episode 15

- Oh, she's a DOCTOR.
- Oh, nice.
The Big Bang Theory Season 2, Episode 8

...the DOCTOR to the stars' urinary tracts.
The Big Bang Theory Season 8, Episode 7

...you're a DOCTOR, you're a DOCTOR.
The Big Bang Theory Season 4, Episode 24