Lay low and fool around with a redhead! (5)
I believe the answer is:
floor
'lay low' is the definition.
(thesaurus)
'fool around with a redhead' is the wordplay.
'fool' becomes 'flo' (I can't explain this - if you can you should give a lot more credence to this answer).
'around' becomes 'o' (a round letter).
'with' says to put letters next to each other.
'a redhead' becomes 'r' (the head/first letter of 'red').
'flo'+'o'+'r'='FLOOR'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for floor that I've seen before include "Knock down; storey" , "fell" , "Knock down with force" , "Disconcert" , "Baffle, confound" .)