Nervy, like Scrooge after heading for London (7)
I believe the answer is:
uptight
'nervy' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for uptight that I've seen before include "Highly-strung" , "Informal word for nervously tense" , "Tense - cross" , "Unable to express one's feelings" , "Ill at ease" .)