Sesame (3)
'sesame' is the definition.
(I've seen this before)
This is the entire clue.
(Another definition for til that I've seen is " Sesame".)
(Other definitions for seed that I've seen before include "Pip; tennis player" , "Top tennis player" , "one very much fancied" , "Plant reproducer" , "Germ; beginning" .)
(Other definitions for open that I've seen before include "gaping" , "William --, English poet" , "Not shut up or hidden" , "Frank and unconcealed" , "Exposed; free" .)
(Other definitions for street that I've seen before include "Town road" , "City road" , "Somerset town; urban way" , "Roadway" , "- Arab; - light" .)