Newblood

"Newblood" was an informal term for Time Lords of newer Houses. Newblood Time Lords were Loomed with a secondary heart from the outset. For them, a change of body was as trivial as a change of fashion. Newblood Time Lords never played Eighth Man Bound. (PROSE: Christmas on a Rational Planet)

At the auction for the Relic, the Shift wondered if the Eighth Doctor was representing one of the newblood Houses. (PROSE: Alien Bodies)

Behind the scenes
Although the term implies there is such a thing as an "oldblood", the term is never used in DWU stories. "Oldblood" does make an appearance in fiction, however.