Physical education likely to start in a day? Make an appeal! (5)
I believe the answer is:
plead
'make an appeal' is the definition.
(I've seen this in another clue)
'physical education likely to start in a day?' is the wordplay.
'physical education' becomes 'pe'.
'to start' indicates taking the first letters.
'in' indicates putting letters inside.
'day?' becomes 'd' (abbreviation for day).
The first letter of 'likely' is 'l'.
'pe' placed around 'l' is 'ple'.
'ple'+'a'+'d'='PLEAD'
(Other definitions for plead that I've seen before include "Argue (a position in court)" , "State whether one is guilty or not" , "Respond to charge" , "Appeal earnestly" , "Argue (for a cause)" .)