Continent - as I am to start with (4)
I believe the answer is:
asia
'continent' is the definition.
(Asia is an example)
'as i am to start with' is the wordplay.
'to start with' says to take the initial letters.
The initial letter of 'am' is 'a'.
'as'+'i'+'a'='ASIA'
(Other definitions for asia that I've seen before include "group of countries" , "A great deal of land" , "Put out" , "Continent of the Hindu Kush" , "Earth's largest continent" .)