Cocaine dealer possibly a lecturer in online talk describing some mountain-tops (4-7)

I believe the answer is:

snow-mantled

'describing some mountain-tops' is the definition.
(snow-mantled means covered in snow)

'cocaine dealer possibly a lecturer in online talk' is the wordplay.
'cocaine dealer possibly' becomes 'snow man' (someone selling cocaine or 'snow').
'a lecturer' becomes 'l' (abbreviation for lecturer).
'in' indicates putting letters inside.
'online talk' becomes 'TED' (as in TED Talks).
'l' going inside 'ted' is 'tled'.
'snowman'+'tled'='SNOW-MANTLED'

I've seen this clue in The Independent.

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