Since (7)
'since' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for because that I've seen before include "For the reason that" , "On account of" , "Owing to" , "Since" , "Beginning to explain" .)
'since' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ago that I've seen before include "(Years) before the present time" , "Back (in time)" , "Time past" , "Earlier, gone by" , "In past times" .)