[usually singular] an unpleasant look, smile or comment that shows you do not respect somebody/something ‘And who are you, then?’ he asked with a sneer in his voice. A faint sneer of satisfaction crossed her face. See related entries: Facial expressions Word Origin late Middle English: probably of imitative origin.Extra examples Her lips twisted into a sneer. The prime minister resisted a sneer at his opponent’s misfortune. The smile slowly turned into a sneer.