A large tree or a small plant on a mountainside (6)
I believe the answer is:
alpine
'a small plant on a mountainside' is the definition.
I can't judge whether this definition defines the answer.
'a large tree' is the wordplay.
'large' becomes 'l'.
'tree' becomes 'pine' (pine is a kind of tree**).
'a'+'l'+'pine'='ALPINE'
'or' acts as a link.
Can you help me to learn more?
(Other definitions for alpine that I've seen before include "Relating to high mountains" , "Nepali (anag.)" , "seen in rocky state?" , "Plant of high mountains" , "Relating to a European mountain range" .)