Plant, entirely lead-free (5)
I believe the answer is:
holly
'plant' is the definition.
(I know that holly is a type of angiospermous tree)
'entirely lead-free' is the wordplay.
'entirely' becomes 'wholly' (I've seen this before).
'lead-free' means to remove the first letter (the letter which leads the word is removed).
'wholly' with its initial letter taken off is 'HOLLY'.
(Other definitions for holly that I've seen before include "Shrub with scarlet berries" , "Prickly tree" , "Prickly Christmas decoration" , "Seasonal shrub" , "Girl" .)