Tree of religious significance about the end of April (5)
I believe the answer is:
holly
'tree' is the definition.
(holly is a kind of tree)
'religious significance about the end of april' is the wordplay.
'religious significance' becomes 'holy' (I can't justify this - if you can you should believe this answer much more).
'about' means one lot of letters goes inside another.
'the end of' says to take the final letters.
The last letter of 'april' is 'l'.
'holy' going around 'l' is 'HOLLY'.
'of' is the link.
Can you help me to learn more?
(Other definitions for holly that I've seen before include "Evergreen tree associated with Christmas" , "Tree with prickles" , "Shrub with scarlet berries" , "Prickly tree" , "Tree with red berries" .)