Well, "slave" has a pretty direct main meaning of an oppressed person doing forced labor. The word "master" is much milder in this regard (compare "master's deg

Well, "slave" has a pretty direct main meaning of an oppressed person doing forced labor. The word "master" is much milder in this regard (compare "master's degree" and "slave's degree"). The word "nonce" in normal usage seems even more removed from any pejorative secondary meanings.