Pertaining to or resembling either Cato the censor (died 149 b. c.) or Cato Uticensis (95-46 b. c.), Romans, both remarkable for severity of manners and morals; hence, grave; severe; inflexible.
the GNU version of the Collaborative International Dictionary of English
adjective.
Of, pertaining to, or resembling, the stern old Roman, Cato the Censor; severe; inflexible.