Wiktionary
butter bean
n. Any of several beans, including the lima bean, sieva bean, wax bean, and civet bean.
WordNet
butter bean
n. bush bean plant cultivated especially in southern United States having small flat edible seeds [syn: sieva bean, butter-bean plant, lima bean, Phaseolus lunatus]
small flat green bean similar to lima beans [syn: sieva bean, butterbean, civet bean]
Usage examples of "butter bean".
A long green snake froze us for a second, then it disappeared into the butter bean vines.
The stone was as big as a butter bean, and it caught the rays of daylight and cast tiny shards of lights around the room as she moved her hand.