Odd situation makes a permanent mark (5)

I believe the answer is:

stain

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

'a permanent mark' is the definition.
'stain' can be an answer for 'mark' (synonyms). I am not certain of the 'a permanent' bit.

'odd situation' is the wordplay.
'odd' means one should take alternating letters.
The alternating letters of 'situation' are 'STAIN'.

'makes' is the link.

Can you help me to learn more?

(Other definitions for stain that I've seen before include "Discoloured patch" , "Discolour - blemish" , "Taint" , "Discoloured mark" , "Satin (anag.)" .)

I've seen this clue in the Sydney Morning Herald.

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.