In truth, the depression is lengthy! (3)

I believe the answer is:

rut

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

'depression is lengthy' is the definition.
I can't tell whether this definition defines the answer.

'in truth the' is the wordplay.
'in' indicates the answer is hidden within the clue.
'RUT' is hidden in the letters of 'truth the'.

Can you help me to learn more?

(Other definitions for rut that I've seen before include "occupying male deer in autumn" , "Wheel-furrow" , "Kind of groove or fixed habit" , "Deep track worn as by wheel" , "does get followed during this" .)

I've seen this clue in the Evening Standard.

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.