Some neck from last of mountaineers on cliff (5)
I believe the answer is:
scrag
'some neck' is the definition.
(I've seen this before)
'last of mountaineers on cliff' is the wordplay.
'last of' says to take the final letters.
'on' is a charade indicator (letters next to each other).
'cliff' becomes 'crag' (crag is a kind of cliff).
The final letter of 'mountaineers' is 's'.
's'+'crag'='SCRAG'
'from' is the link.
(Other definitions for scrag that I've seen before include "Poor quality meat - throttle" , "Collar" , "End of neck - beat up" , "Bony part of the neck" , "The inferior end of a neck of mutton" .)