19 across
Brief
note
concerning
one
Conservative
snorting
cocaine
(7)
Brief note concerning one Conservative snorting cocaine (7)
hints
0
checks
0
hints
The definition is at the beginning of the clue.
How the clue works
Brief is the definition, meaning terse or laconic. Take LA (a note in the solfa scale) and insert C (cocaine) into it — the 'snorting' being the containment indicator — then add ON (concerning), I (one) and C (Conservative), giving LACONIC.