Big check-printing co.

• Payroll service co
• Payroll service giant, initially
• Big payroll service co.
• An ester of adenosine that is converted to ATP for energy storage
• Big name in payroll
• Payroll service initials
• Data processing by a computer
• Payroll services company

Wiktionary Word definitions in Wiktionary
n. (initialism of adenosine diphosphate English)