Still face of impassive mountain dweller (4)
I believe the answer is:
yeti
'mountain dweller' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
'still face of impassive' is the wordplay.
'still' becomes 'yet' (yet can mean still or so far).
'face of' says to take the initial letters.
The first letter of 'impassive' is 'i'.
'yet'+'i'='YETI'
Can you help me to learn more?
(Other definitions for yeti that I've seen before include "seeks him in the Himalayas" , "associate it with Tibet" , "A sort not reliably recorded" , "Anthropoid cryptid" , "Teh Abominable Snowman" .)