Meaning of “down” - Learner’s Dictionary

down

adjective [ never before noun ] uk us /daʊn/
SAD

B2 sad:

What's the matter? You look a bit down today.
NOT WORKING

If a computer or machine is down, it is temporarily not working:

The network was down all morning.

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