Nervous, coming from Channel Islands on board (9)
I believe the answer is:
excitable
'nervous' is the definition.
(similar in meaning)
'from channel islands on board' is the wordplay.
'from' becomes 'ex' ('from' in Latin).
'channel islands' becomes 'CI'.
'on' means one lot of letters go next to another.
'board' becomes 'table' (synonyms).
'ex'+'ci'+'table'='EXCITABLE'
'coming' acts as a link.
This may not be correct. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for excitable that I've seen before include "Hot-headed" , "Easily stimulated" , "Highly strung - easily roused" , "Volatile" , "Highly-strung" .)