Like erupting mountain with very old clan oddly in charge (8)
I believe the answer is:
volcanic
'like erupting mountain' is the definition.
Both the definition and answer are adjectives. Maybe you can see a link between them that I don't see?
'very old clan oddly in charge' is the wordplay.
'very' becomes 'v' (common abbreviation).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'oddly' indicates an anagram (letters in an odd order).
'in charge' becomes 'ic' (abbreviation for 'in charge').
'clan' anagrammed gives 'lcan'.
'v'+'o'+'lcan'+'ic'='VOLCANIC'
'with' is the link.
Can you help me to learn more?
(Other definitions for volcanic that I've seen before include "Explosively unstable, rock say" , "Of Etna or Vesuvius?" , "given to sudden outbursts" , "Of lava-producing fissures" , "Relating to eruption in earth's surface" .)