Crossword Genius

Subject to regular current variation (5)

Ross

I believe the answer is:

tidal

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

'subject' is the definition.
Although both the answer and definition are adjectives, I cannot see how they can define each other.

I don't understand the rest of the clue.

Can you help me to learn more?

(Other definitions for tidal that I've seen before include "__ wave; tsunami" , "What a bore may be" , "Type of wave" , "Subject to moon's pull" , "(Waters) subject to moon/sun" .)

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.