Create problems underwriting height and size of field (7)
I believe the answer is:
hectare
'size of field' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'create problems underwriting height' is the wordplay.
I cannot really understand how this works, but
an anagram of 'create' is 'ectare' which is within the answer.
'height' could be 'h' (abbreviation in geometry) and 'h' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'and' acts as a link.
Can you help me to learn more?
(Other definitions for hectare that I've seen before include "Ten thousand square metres" , "10,000 square metres" , "Metric land area" , "10,000 squaer metres" , "Metric unit of area" .)