Bert's roommate on "Sesame Street" (5)
I believe the answer is:
ernie
'bert's roommate on sesame street' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ernie that I've seen before include "Wise for instance" , "Selector of winning premium bond numbers" , "Male" , "Eric's TV partner" , "Els, for example" .)