BUT or But may refer to:
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths.
Butyric acid (from Greek βούτῡρον, meaning "butter"), also known under the systematic name butanoic acid, abbreviated BTA, is a carboxylic acid with the structural formula CH3CH2CH2-COOH.
A watch battery or button cell is a small single cell battery shaped as a squat cylinder typically 5 to 25 mm in diameter and 1 to 6 mm high—like a button on a garment, hence the name.
Butlins (also Butlin's) is a chain of large holiday camps in the United Kingdom. Butlins was founded by Billy Butlin to provide affordable holidays for ordinary British families.
Butter is a dairy product containing up to 80% butterfat (in commercial products) which is solid when chilled and at room temperature in some regions and liquid when warmed.
Butler University is a private university in Indianapolis, Indiana. Founded in 1855 and named after founder Ovid Butler, the university has over 60 major academic fields of study in six colleges: Lacy School of Business, College of Communication, College of Education, College of Liberal Arts and Sciences, College of Pharmacy and Health Sciences, and Jordan College of the Arts.