The word 双面 is a compound formed by combining the morpheme 双 (shuāng), meaning "double" or "two", with 面 (miàn), meaning "face", "surface", or "side". It is a straightforward modifier-noun structure where "双" quantifies and describes the noun "面", resulting in the literal meaning of "two faces" or "two sides". This term is used both literally, to describe physical objects like double-sided tape (双面胶), and metaphorically, to describe duality in character or situations, such as a "two-faced" personality or a "double-sided" situation with opposing aspects.