Apropos

[Sarah]

adj. in timely or appropriate manner/context; this can also mean in addition

[Mark Zuckerberg]

When youre looking to say something [appropriate]; real fancy, like to impress someone instead of just saying its suitable or befitting.

[Sarah]

by the way

[Jessica]

Used at start of sentence to link to last sentence.

[Renato]

used to introduce something that is related to or connected with something that has just been said:

[Merna]

With reference to; concerning.