Appeals for some simple assurance (5)
I believe the answer is:
pleas
'appeals' is the definition.
(plea is a kind of appeal)
'some simple assurance' is the wordplay.
'some' indicates the answer is hidden within the clue (some of the parts of the word are used).
'PLEAS' is hidden within 'simple assurance'.
'for' acts as a link.
(Other definitions for pleas that I've seen before include "Entreats" , "Excuses, pretexts" , "Urgent entreaties" .)