Against help with sweetheart suppressing desires (9)
I believe the answer is:
alongside
'against' is the definition.
I can't tell whether this definition defines the answer.
'help with sweetheart suppressing desires' is the wordplay.
'help' becomes 'aid' (synonyms).
'with' means one lot of letters go next to another.
'sweetheart' becomes 'e' (the heart/centre of 'sweet').
'suppressing' means one lot of letters goes inside another.
'desires' becomes 'long s' (longing is a kind of desiring).
'aid'+'e'='aide'
'aide' enclosing 'longs' is 'ALONGSIDE'.
Can you help me to learn more?
(Other definitions for alongside that I've seen before include "next door" , "Age-old sin (anag.)" , "Next to, another boat perhaps" , "Next to - alien dogs (anag)" , "Lying next to, as a boat might be" .)