Crossword Genius

Left student absorbed by reason mainly for a thickening of tissue (6)

Ross

I believe the answer is:

callus

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

'a thickening of tissue' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.

'left student absorbed by reason mainly' is the wordplay.
'left' becomes 'l' (common abbreviation).
'student' becomes 'l' (as in L-plates for learner drivers).
'absorbed by' means one lot of letters goes inside another.
'reason' becomes 'cause' (I've seen this in another clue).
'mainly' means to remove the last letter.
'l'+'l'='ll'
'cause' with its final letter taken off is 'caus'.
'll' going inside 'caus' is 'CALLUS'.

'for' is the link.

Can you help me to learn more?

(Other definitions for callus that I've seen before include "Area of hard skin" , "This thick-skinned" , "Thickened skin patch" , "Corn" , "Skin problem" .)

I've seen this clue in The Telegraph.
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.