The Spanish word 'pilcha', meaning 'clothing' or 'garment', comes from the Mapudungun (the language of the Mapuche people of south-central Chile and southwestern Argentina) word 'pulcha' meaning 'wrinkle'. This semantic evolution from 'wrinkle' to 'clothing' likely developed through the association of wrinkles in fabric with clothing items, particularly in the context of traditional textiles and garments in indigenous Mapuche culture.

There are no commonly used Spanish words that share the same Mapudungun etymology as 'pilcha', as this word represents a direct borrowing from an indigenous American language rather than deriving from Latin or other Indo-European roots common to many Spanish words.

There are no etymologically related English words to 'pilcha', as it comes from Mapudungun, an indigenous American language family that is completely unrelated to the Indo-European language family from which English derives.