Implicit in endless data cited (5)
I believe the answer is:
tacit
'implicit' is the definition.
(similar in meaning)
'in endless data cited' is the wordplay.
'in' says the answer is hidden in the clue.
'TACIT' can be found hidden inside 'endless data cited'.
(Other definitions for tacit that I've seen before include "Silently understood" , "Silent but implied" , "Wordless" , "Unspoken but understood" , "Respect, admiration" .)