Drugs in small on-line trysts? (7)
I believe the answer is:
sedates
'drugs' is the definition.
(drugs with a sedative)
'small on-line trysts?' is the wordplay.
'small' becomes 's' (abbreviation - e.g. clothes size).
'on-line' becomes 'e' (abbreviation for electronic, e.g. in ecommerce).
'trysts?' becomes 'dates' (tryst is a kind of date).
's'+'e'+'dates'='SEDATES'
'in' is the link.
(Other definitions for sedates that I've seen before include "Treats with soothing or sleeping drugs" , "keeps quiet" , "Anaesthetises" , "Calms" .)