Crossword Genius

A noted figure, but remiss (3)

Ross

I believe the answer is:

lax

I'm a little stuck... Click here to teach me about this clue!

Here is my best explanation:

'remiss' is the definition.
(I've seen this before)

I don't understand how the remainder of the clue works.

Can you help me to learn more?

This clue was last seen in Evening Standard