Rectitudinous comes to us straight from Late Latin rectitudin-, rectitudo (English added the -ous ending), which itself ultimately derives from the Latin word rectus, meaning both "straight" and "right." (Other rectus descendants in English include rectitude, of course, and rectilinear, rectangle, and rectify.) In one of its earliest known print appearances, in the year 1897, it was used in the phrase "notoriously and unctuously rectitudinous." Although rectitude often expresses an admirable moral integrity, rectitudinous has always had a less flattering side. It can suggest not only moral uprightness but also a displeasing holier-than-thou attitude.