Butter

A soft, fatty foodstuff made by churning the cream of milk (generally cow's milk).

Any of various foodstuffs made from other foods or oils, similar in consistency to, eaten like or intended as a substitute for butter (preceded by the name of the food used to make it).

"peanut butter"

Any specific soft substance.

"butter of antimony; butter of arsenic"

A smooth plane landing.

To spread butter on.

"Butter the toast."

To move one's weight backwards or forwards onto the tips or tails of one's skis or snowboard so only the tip or tail is in contact with the snow.

To increase (stakes) at every throw of dice, or every game.

Someone who butts, or who butts in.