Con-trōl'ler, n.

n. [From control, v. t.; Fr. contrôleur, Norm. Fr. countre-rouler.]

1. An officer appointed to keep a counter register of accounts, or to oversee, control, or verify the accounts of other officers. [More commonly written comptroller.]
2. One who controls or restrains; one that has the power or authority to govern or control.

The great controller of our fate Designed to be man, and lived in low estate. Dryden.