cofactor /kō-fakˈtər/

1. A factor which occurs along with other factors in multiplication
2. A nonprotein organic molecule or a metallic ion that binds with an enzyme and is essential to the enzyme's activity (biology)

• cholic
• butter-woman
• butterwort
• butterworts
• buttery
• buttery-bar
• buttery-bars
• buttery-fingered
• buttery fingers
• buttery-hatch
• buttery-hatches
• buttes
• but that
• butthead
• buttheads
• butt hinge
• butt hinges
• butties
• butt in
• butting
• buttle
• buttock
• buttocked
• buttocking
• buttock-mail