butter bean
noun
1.
a variety of small-seeded lima bean,
Phaseolus lunatus,
grown in the southern U.S.
2.
Midland and Southern U.S.
any type of lima bean.
Also,
butterbean
.
Origin
1810-20
British Dictionary definitions for
butter bean
butter bean
noun
1.
a variety of lima bean that has large pale flat edible seeds and is grown in the southern US