Seconds served with fish and flower head (5)
I believe the answer is:
spike
'flower head' is the definition.
'spike' can be an answer for 'head' (thesaurus). I'm not sure about the 'flower' bit.
'seconds served with fish' is the wordplay.
'seconds' becomes 's'.
'served with' means one lot of letters go next to another.
'fish' becomes 'pike' (pike is a kind of fish).
's'+'pike'='SPIKE'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for spike that I've seen before include "Large nail; thwart" , "Long sharp-pointed implement" , "comedian of old" , "spear" , "Decide not to run" .)