At the same time (14)
'at the same time' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for meanwhile that I've seen before include "simultaneously" , "In the interim" , "On the other hand" , "For the moment" , "in intervening period" .)
'at the same time' is the definition.
(synonyms)
This is all the clue.
(Another definition for simultaneously that I've seen is " at the same time".)