(SERIOUS) [adjective] - serious and calmIn fact the whole wedding was a sober affair - no dancing, just people standing around in groups chatting politely.Anthony was in a very sober mood - I scarcely heard him laugh all night.On a more sober (= serious) note, there have been one or two break-ins in the building recently.The fashionable colours this autumn are very sober (= not bright) - dull greys and greens and dark browns predominate.
SOBER
Meaning of SOBER in English
Cambridge English vocab. Кембриджский английский словарь. 2012