Silly name given to a single plant (7)
I believe the answer is:
anemone
'plant' is the definition.
(anemone is a kind of plant)
'silly name given to a single' is the wordplay.
'silly' indicates anagramming the letters.
'given to' is a charade indicator (letters next to each other).
'a single' becomes 'one' ('one' can be a synonym of 'single').
'name' with letters rearranged gives 'anem'.
'anem'+'one'='ANEMONE'
(Other definitions for anemone that I've seen before include "Woodland plant, eg the windflower" , "Plant of the buttercup family with brightly coloured flowers" , "Windflower - sea creature" , "perennial" , "Plant with brightly coloured flowers - found also in sea" .)