The word "bean" and its Germanic cognates (e.g., Bohne) have existed in common use in West Germanic languages since before the 12th century, referring to broad beans and other pod-borne seeds. This was long before the New World genus Phaseolus was known in Europe. After Columbian-era contact between Europe and the Americas, use of the word was extended to pod-borne seeds of Phaseolus, such as the common bean and the runner bean, and the related genus Vigna. The term has long been applied generally to many other seeds of similar form, such as Old World soybeans, peas, chickpeas (garbanzo beans), other vetches, and lupins, and even to those with slighter resemblances, such as coffee beans, vanilla beans, castor beans, and cocoa beans. Thus the term "bean" in general usage can mean a host of different species.
Seeds called "beans" are often included among the crops called "pulses" (legumes), although a narrower prescribed sense of "pulses" reserves the word for leguminous crops harvested for their dry grain. The term bean usually excludes legumes with tiny seeds and which are used exclusively for forage, hay, and silage purposes (such as clover and alfalfa). According to the United Nations Food and Agriculture Organization the term bean should include only species of Phaseolus; however, enforcing that prescription has proven difficult for several reasons. One is that in the past, several species, including Vigna angularis (adzuki bean), mungo (black gram), radiata (green gram), and aconitifolia (moth bean), were classified as Phaseolus and later reclassified. Another is that it is not surprising that the prescription on limiting the use of the word, because it tries to replace the word's older senses with a newer one, has never been consistently followed in general usage.