That person at a party or any other social gathering who is the first person to say no to a zany idea or want to go home. Example: John, I can't believe you, of all people, are being such a lame-inator. It's only midnight.
LAME-INATOR
Meaning of LAME-INATOR in English
Slang English vocab. Английский сленговый словарь. 2012