A comic book character without a code name is no comic book character at all; at least, that's what conventional wisdom (and marketing) seem to be saying. Don't get us wrong — Tony Stark is a pretty cool-sounding name, but Iron Man is a much punchier—literally and figuratively—super-heroic name. However, like Tony's moniker, Barry Allen's zippy Flash, or Peter Parker's Spider-Man tag, their names also make a good deal of sense to their respective crime-fighting identities. Tony's exosuit is made from metal (or alloy), Allen is really fast, and Peter is a man infused with the radioactive gene of a spider.
In Star-Lord's case, however, his title doesn't make much sense initially. True, he's out there among the cosmos, but he certainly doesn't seem like much of a lord, unless prison yellow is the new royal look around the galaxy. Depending upon which origin story you go by, Star-Lord was either granted his title by the Master of the Sun — a moniker which he literally stole from a competitor — or, in his more recent incarnation, his title is actually an ironic jest upon the character's birthright. See, after Peter Quill leaves Earth in a stolen Kree ship, he later discovers that his father actually is a star lord named J'Son, ruler of Spartax. His father wants him to follow in his footsteps, and rule the Spartoi Empire as the Star-Lord, but Quill has no interest in galactic politics, conquest, or petty despotism. Parting on meh terms with pops, he shirks his royal duties, carrying on paradoxically as "Star-Lord" while he runs around the galaxy with the Guardians.