Linguistically it means : sad or sorrowful
Sadge, is a nickname for the word "Sagittarius.
But in modern days Sadge is an emote on Twitch depicting a flattened version of Pepe the Frog with a sad, disappointed expression and a downward glance, and a variation on Pepega.
The emote is commonly used as a reaction to convey sadness or depression in chats on Twitch, but also appears in memes and a form of copypasta elsewhere online
The word Sagittarius originates from ancient Latin and means "the archer," or "the one who shoots arrows with an arrow." This name has been used by many cultures throughout history.