Definition of "PUP"

(computing) Acronym of potentially unwanted program: software that most computer users do not want on their computers, such as adware.  examples

(insurance) Paid up  examples

(biochemistry) Prokaryotic ubiquitin-like protein  examples

(computing) Initialism of Private Use Plane: either of the two Unicode planes (planes 15 and 16) reserved for private use.  examples