poplar /popˈlər/

1. A genus (Populus) of rapidly growing trees of the willow family, including aspen, white poplar, black poplar (with its variety Lombardy poplar), cottonwood, etc; widespread in northern temperate regions
2. The tulip tree, tulip poplar (US)

• butter-box
• butter-boxes
• butter-bump
• butter-bumps
• butterbur
• butterburs
• butter cloth
• butter-cooler
• butter-coolers
• butter cream
• buttercup
• buttercups
• butter dish
• butter dishes
• butterdock
• buttered
• buttered eggs
• butterfat
• butterfats
• butterfingered
• butterfingers
• butterfish
• butterfishes
• butterflies
• butterflies in the stomach