Annoyance after mislaying leader when welcoming European association (6)
I believe the answer is:
league
'association' is the definition.
(I know that league is a type of association)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for league that I've seen before include "Group of clubs; distance" , "Group of countries in mutual cooperation" , "Combination of groups for a purpose, sports clubs perhaps" , "'Nautical measure, about 3? miles (6)'" , "See 11" .)