Also endlessly sketched prince (6)
I believe the answer is:
andrew
'prince' is the definition.
(Prince Andrew is an example)
'also endlessly sketched' is the wordplay.
'also' becomes 'and' (I've seen this before).
'endlessly' means to remove the last letter.
'sketched' becomes 'drew' (I've seen this before).
'and' with its last letter removed is 'an'.
'an'+'drew'='ANDREW'
(Other definitions for andrew that I've seen before include "Boy's name" , "November thirtieth is this saint's day" , "- Motion, Poet Laureate" , "Scotland's patron saint" , "Patron saint of Scotland, Russia" .)