Everywhere at the same time (11)
I believe the answer is:
omnipresent
'everywhere at the same time' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for omnipresent that I've seen before include "Found everywhere" , "travelling all over the place" , "Existing everywhere" , "(Of God) everywhere simultaneously" , "Ubiquitous" .)