Non-sexual adult baby (those who appear to be paraphilic infantalist but lack the true paraphilia). Pertains to one who like baby-like; enjoying wearing and possibly using diapers, sucking pacifier, drinking from a bottle or sippy cup, sleep in a crib, ect. This is an accurate definition for those that appear to be paraphilic infantalist but lack the sexual elements necessary for a fetish. This is not a fetish, this is a lifestyle.
A man who wears a diaper shirt and overalls during the day and a blanket sleeper at night is showing elements of NSAB.
A girl who is not a drug user who is sucking a pacifier is showing elements of NSAB.
A variation of the word noob but much more comical, some say it was invented by a genie called bob, other more sensible people think it was just another script kiddie with too much time on his hands. Often Used in internet slagging matches.