Steady, sober (5)
I believe the answer is:
staid
I believe this is a double definition.
'steady' is the first definition.
(thesaurus)
'sober' is the second definition.
(synonyms)
(Other definitions for staid that I've seen before include "Dully unadventurous" , "Very conventional and dull" , "Conventional (character)" , "Sedate and serious" , "Settled" .)