Like one area in largest continent (4)
I believe the answer is:
asia
'largest continent' is the definition.
(I've seen this in another clue)
'like one area' is the wordplay.
I cannot quite understand how this works, but
'like' could be 'as' and 'as' is present in the answer.
'one' could be 'i' (Roman numeral) and 'i' is found within the answer.
'area' could be 'a' (maths abbreviation) and 'a' is present in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'in' acts as a link.
Can you help me to learn more?
(Other definitions for asia that I've seen before include "Great continent" , "Large area" , "Earth's largest continent" , "populous region" , "group of countries" .)