Unbidden is an adjective that means unsolicited or uninvited.

The German word bitten (BIT en) means ‘to ask.’ This word has evolved into the word bid, which means ‘to command or invite.’ When someone does something unbidden they do it without having been asked or demanded. For example: It was nice of Johnny to make the unbidden offer of helping with the cookout, especially since he wasn’t even requested to do so. But after eating the horrible omelets he cooked for us, we soon realized why no one requested him to help with the cookout.