The word "willan" is derived from the Old English verb "willian" which means "to want, to desire". Its origin can be traced back to the Proto-Germanic word "wiljaną", which also means "to want, to wish". This Proto-Germanic word is further derived from the Proto-Indo-European root word "welh-", meaning "to wish, to desire". Over time, "willian" evolved into "willen" in Middle English and eventually into "will" in Modern English, while "willan" itself became obsolete.