What's said to be dismissed at all times and everywhere (10)
I believe the answer is:
throughout
'at all times and everywhere' is the definition.
(throughout means always or consistently)
'what's said to be dismissed' is the wordplay.
'what's said to be' indicates a 'sounds like' (homophone) clue.
'dismissed' becomes 'threw out' ('throw out' can be a synonym of 'dismiss').
'threwout' is a homophone of 'THROUGHOUT'.
(Other definitions for throughout that I've seen before include "from start to finish" , "Completely" , "Everywhere" , "during the entire proceedings" , "all the time" .)