An EXTENSION of his ability
to leap buildings...
The Big Bang Theory Season 1, Episode 2
...adult EXTENSION programme
at the university.
Breaking Bad Season 3, Episode 9
I believe this is an EXTENSION
of the death metaphor.
The Big Bang Theory Season 2, Episode 8
And by EXTENSION, you know,
neither are you.
Breaking Bad Season 2, Episode 12
That means it's better than his research,
and by EXTENSION, of course, yours.
The Big Bang Theory Season 4, Episode 3