Opening yard by church good for carrying in deceased (8)

'opening yard' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?

'church good for carrying in deceased' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'good for' becomes 'yg' (I am not sure about this - if you are sure you should believe this answer much more).
'carrying' indicates putting letters inside.
'in' is an insertion indicator.
'deceased' becomes 'late' (late can mean deceased).
'ch' going inside 'yg' is 'ychg'.
'ychg' inserted within 'late' is 'LYCHGATE'.

'by' is the link.

Can you help me to learn more?