Definition of the word when

The word "when" comes from Old English and is related to the Proto-Germanic word "*hwan," which was also the source of the Modern German word "wan" meaning "at what time." This Proto-Germanic word is derived from the Proto-Indo-European root "*kʷe" or "*kʷeh₂," which signified "at what point" or "at what moment." In Old English, "when" was spelled "hwen" and was used as both a relative adverb, meaning "at the time when," and an interrogative adverb, meaning "at what time." The word has remained largely unchanged in Modern English, with the main difference being the spelling, which was standardized to "when" in the 15th century. I hope that's the "when" you were looking for!