- a stoppage; delay or hindrance
- the act of stopping forcibly and robbing
- Informal the act of overcharging
- the amount of liquid retained or delayed during fractional distillation and certain types of solvent extractions
- the free volume between the resin particles in an ion exchange column
- Physics the amount of fissionable material being processed or in storage for irradiation in a reactor cycle
- An interruption or a delay: What's the holdup? We're in a hurry.
- An armed robbery.
- Alternative spelling of hold-up.