gregarious?

[keannu]

Is "gregarious" a common word? Solving some test's voca part, I encountered some big words and one of them is like this, and I wonder if an average native speaker knows about this, or he also has to endeavor to study these kinds of words.

Q. a: I think John is a clever student.
b: I do too, Actually,he is really c
a.clumsy b.gregarious c.brilliant d.shallow

[SoothingDave]

It's common enough.

[bhaisahab]

It's common enough.

Yes, it is.