The one cutting the lawn is not from my family (2-3)
I believe the answer is:
in-law
'family' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'the one cutting the lawn is not from my' is the wordplay.
I cannot really see how this works, but
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
an anagram of 'lawn' is 'nlaw' which is present in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for in-law that I've seen before include "Family member, by marriage" , "Meghan to Harry's family?" , "Relative by marriage" , "Spouse's relation" , "Near relative" .)