rando [ran-doh] noun
an unpredictable, awkward and often creepy individual. a rando is always there in the background, even though no one invited him. Randos tend to be isolated within large groups; they sit in corners and lurk in the shadows of others. Even though everyone is aware of the presence of a rando, no one knows anything about him or her and therefore randos are often unwittingly ignored.
1150–1200; Middle English Would you like some tea and randuh~