They give you something to think about (5)
I believe the answer is:
clues
'they' is the definition.
Both the definition and answer are plural nouns.
Maybe they are linked in a way I don't understand?
'you something to think about' is the wordplay.
I cannot quite see how this works, but
'you' could be 'u' (commonly used in online communication) and 'u' is located in the answer.
'about' could be 'c' (abbreviation for 'circa') and 'c' is located in the answer.
The remaining letters 'les' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'give' acts as a link.
Can you help me to learn more?
(Other definitions for clues that I've seen before include "Crossword aids" , "Indications" , "Here, they're across and down" , "Hints (that you're looking at?)" .)