It's present in concrete (6)
I believe the answer is:
actual
I believe this clue is a double definition.
'it's present' is the first definition.
(thesaurus)
'concrete' is the second definition.
(I've seen this in another clue)
'in' acts as a link.
(Other definitions for actual that I've seen before include "Real and current (6)" , "Existing in fact, current" , "Real, authentic" , "De facto" , "Real and concrete, not imaginary" .)