Attempt to include a carrier (4)
I believe the answer is:
tray
'carrier' is the definition.
(I've seen this before)
'attempt to include a' is the wordplay.
'attempt' becomes 'try' (I've seen this before).
'to include' means one lot of letters goes inside another.
'try' going around 'a' is 'TRAY'.
(Other definitions for tray that I've seen before include "Flat surface for carrying things" , "Kitchen carrier" , "three" , "canteen item" , "Carrier (for eg, crockery, food)" .)