棉衫 (mián shān) literally combines 棉 (mián), meaning 'cotton', and 衫 (shān), a classical term for 'shirt' or 'upper garment'. Together, it refers specifically to a shirt made primarily of cotton fabric — valued for its breathability, softness, and comfort in everyday wear. Unlike more formal terms like 衬衫 (chènshān, dress shirt), 棉衫 emphasizes material composition rather than cut or occasion.

This word is commonly used in casual or descriptive contexts — for example, when shopping for summer clothing, describing someone’s outfit, or distinguishing natural-fiber garments from synthetic ones. It appears frequently in e-commerce listings, clothing labels, and lifestyle conversations. While 衫 alone can be archaic or poetic, pairing it with 棉 gives the compound a clear, modern, functional meaning focused on textile quality and comfort.