Tern flying by church in resort (6)
I believe the answer is:
centre
'resort' is the definition.
(as in a tourist resort or tourist centre)
'tern flying by church' is the wordplay.
'flying' indicates anagramming the letters.
'by' means one lot of letters go next to another.
'church' becomes 'ce' (abbreviation for Church of England).
'tern' anagrammed gives 'ntre'.
'ntre' put after 'ce' is 'CENTRE'.
'in' acts as a link.
(Other definitions for centre that I've seen before include "and this may follow 26, 25 [LEFT RIGHT]" , "Middle, core" , "Exact middle point" , "See 1" , "The point equidistant from everything" .)