Meaning of “long” - Learner’s Dictionary

long

adverb uk us /lɒŋ/

A2 for a long time:

We didn't have to wait long for the train.
The band played long into the night.
as long as

B1 used when you are talking about something that must happen before something else can happen:

You can play football as long as you do your homework first.
before long

B2 soon:

He'll be home before long.
long ago

If something happened long ago, it happened a great amount of time ago.

no longer/not any longer

B1 not now:

He no longer works here.

(Definition of “long adverb” from the Cambridge Learner’s Dictionary © Cambridge University Press)