The Spanish word 'falda' meaning 'skirt' has Germanic roots, tracing back through Frankish *falda meaning 'fold, pleat' to the Germanic word 'faldan' meaning 'to fold'. This etymology makes intuitive sense when you think about how traditional skirts were made with pleats or folds of fabric.

Some related Spanish words include 'faldón' (a long flap or tail of a garment), 'faldar' (skirt of armor), and 'faldilla' (short skirt). All these words share the basic concept of a folded or hanging piece of fabric or material.

The English word 'fold' is actually a cousin of 'falda', as they both come from the same Germanic root 'faldan'. While 'fold' maintained its original meaning of bending or pleating something, the Spanish 'falda' specialized to refer specifically to a pleated or folded garment - a skirt. The English words 'folder' and 'foldable' are other obvious relatives that maintained the original sense of folding.