Relatively mature, or about to be led astray (5)

I believe the answer is:

older

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

'relatively mature' is the definition.
I can't judge whether this defines the answer.

'about to be led astray' is the wordplay.
'about' means one lot of letters goes inside another.
'to' becomes 'or' (I can't explain this - if you can you should believe this answer much more).
'astray' indicates an anagram.
'led' with letters rearranged gives 'lde'.
'or' enclosing 'lde' is 'OLDER'.

'or' is the link.

Can you help me to learn more?

(Other definitions for older that I've seen before include "More advanced in point of time" , "more history" , "Increasingly mature" , "Getting on" , "as we all will be tomorrow" .)

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.