Untidy heap surrounds trench at graveyard, it's observed (7)
I believe the answer is:
epitaph
'graveyard it's observed' is the definition.
I can't tell whether this definition defines the answer.
'untidy heap surrounds trench' is the wordplay.
'untidy' indicates anagramming the letters.
'surrounds' means one lot of letters goes inside another.
'trench' becomes 'pit' (trench is a type of pit).
'heap' with letters rearranged gives 'eaph'.
'eaph' going around 'pit' is 'EPITAPH'.
'at' is the link.
Can you help me to learn more?
(Other definitions for epitaph that I've seen before include "Memorial words" , "Commemorative inscription" , "Words carved on a gravestone" , "Words describing a dead person (7)" , "Gravestone inscription" .)