Strictly applied it's neither easy nor slow (4,3,4)

I believe the answer is:

hard and fast

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

'slow' is the definition.
Both the definition and answer are adjectives.
Maybe they are linked in a way I don't understand?

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for hard and fast that I've seen before include "Fixed and definitive" , "(Of rules) invariable" , "Stupid person" , "Not able to be changed" , "Not moving" .)

I've seen this clue in The Globe and Mail.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.