A person who eats breakfast or a meal typically served at breakfast time.
From 'breakfast' + '-er' (one who does something). This agent noun formation was productive in English, creating 'breakfaster' to describe someone characterized by breakfast-eating.
Some people are 'breakfasters' while others skip it entirely—language actually categories people by their eating habits! This word is rare in modern usage but shows how English can turn almost any activity into a person-identity.
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