Feeling anxious, having lost ID in quayside scuffle (6)
I believe the answer is:
queasy
'feeling anxious' is the definition.
(queasy can mean feeling sick or anxious)
I don't understand how the rest of the clue works.
(Other definitions for queasy that I've seen before include "Squeamish - nauseous" , "Nauseous or bilious" , "Feeling slightly sick, maybe with indigestion" , "Sickish" , "Ailing" .)