Burrow’s innermost part — hard to get to the end (5)
I believe the answer is:
earth
'burrow's' is the definition.
(I've seen this before)
'innermost part hard to get to the end' is the wordplay.
'innermost part' becomes 'ear' (ear is a kind of part. I am not sure about the 'innermost' bit.).
'hard' becomes 'h' (abbreviation used in pencil classifications).
'to' means one lot of letters go next to another (I've seen this in other clues).
'to the end' says to take the final letters.
The last letter of 'get' is 't'.
'h' put after 't' is 'th'.
'ear'+'th'='EARTH'
Can you help me to learn more?
(Other definitions for earth that I've seen before include "Heart (anag)" , "Lair; planet" , "Ground - globe - soil" , "cost of which is very high" , "Soil; fox's lair" .)