A Member Of A Group Of Patrons Becomes Obviously Intoxicated

Hello everyone, I've been looking for a word to say 'member who has been in a group (Supreme Court, organization, order, etc) the longest time.' In Portuguese there is such a word, but I'm really not sure if it exists in English for all cases mentioned above. My question: What word or...

a member of a group of patrons becomes obviously intoxicated 1