If you're encountering the misspelling "whineer", it is likely a typo for the word "whiner", which means someone who complains a lot. Remember to use the correct spelling to avoid any confusion.
Whiner The whiner complained about everything and everyone, making it impossible to enjoy the party.
Whinger I can't stand when people around me are constantly whingers, complaining about everything without doing anything to change their circumstances.
Whinier My little brother became even whinier when he found out he couldn't play with his toys until after dinner.