Society nowadays is miserable (3)
I believe the answer is:
sad
'miserable' is the definition.
(similar in meaning)
'society nowadays' is the wordplay.
'society' becomes 's' (common abbreviation in names of organisations).
'nowadays' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
's'+'ad'='SAD'
'is' acts as a link.
(Other definitions for sad that I've seen before include "A form of depression in winter, initially" , "Disconsolate" , "Mournful and depressed" , "Melancholy, depressed" , "Winter blues, initially" .)