Meaning of "as" in Essential English Dictionary

as

preposition, conjunction uk strong /æz/ uk weak /əz/

A1 used to describe something’s purpose or someone’s job:

She works as a waitress.
They use their spare bedroom as an office.
as… as

A2 used to compare two things, people, amounts, etc.:

He’s not as tall as his brother.
She earns three times as much as I do.

A2 because:

You can go first as you’re the oldest.

B1 while:

I saw James as I was leaving.

B1 in the same way:

This year, as in previous years, tickets sold very quickly.
as if/as though

used to describe how a situation seems to be:

It looks as if it might rain.
as for

used to talk about how another person or thing is affected by something:

I’m pleased. As for Kyle, I don’t care what he thinks.

(Definition of “as” from the Cambridge Essential Dictionary © Cambridge University Press)