Mountain climbing on rope that can be eased (8)

'mountain climbing on rope that can be eased' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I don't see?

'mountain climbing on rope' is the wordplay.
'mountain' becomes 'alp' (the Alps are a mountain range).
'climbing' says the letters should be written backwards (in a down clue, letters climb up).
'on' says to put letters next to each other.
'rope' becomes 'cable' (cable is a kind of rope).
'alp' in reverse letter order is 'pla'.
'pla'+'cable'='PLACABLE'

Can you help me to learn more?