Miscellaneous, assorted, heterogeneous, motley, promiscuous are comparable when they mean marked by diversity or variety and are applied to the things that make up a group, a collection, or a mass, or to a group, collection, or mass.
Miscellaneous usually implies a mixture of many kinds, showing few signs of selection, and often suggesting dependence on chance.
Assorted (see also ASSORT ) and the related noun assortment also imply a mixture but not a haphazard one; they carry the implications of a selection including various kinds or involving consideration of various tastes or needs.
Heterogeneous is applicable chiefly to masses or groups in which the individuals or the elements are in proximity or close relationship to each other by chance; it suggests not only variety or diversity in the individuals or the elements but also absence of uniformity or unity and little evidence of fusion.
Motley adds to heterogeneous the suggestion of discordance in the individuals or elements or their striking contrast to each other; perhaps from the notion of discordance it is more depreciative than the foregoing terms and is more likely to qualify groups made up of elements felt as inferior or undesirable.
Promiscuous may suggest haphazardness or the appearance of it, but it usually implies selection that is completely devoid of discrimination and that results in disorderly confusion; thus, a miscellaneous acquaintanceship may imply a catholicity of taste, but a promiscuous acquaintanceship implies an absence of taste and good judgment; from a description of a club's membership as heterogeneous one might infer its interesting diversity but from a description of it as promiscuous one can infer only a diversity that is distasteful and senseless from the point of view of the speaker or writer.
For this reason, promiscuous as applied specifically to people or their acts, emotions, and relations stresses not only lack of discrimination, but lack of restriction within bounds set (as by prudence, good sense, or sound morals); thus, promiscuous charity is imprudently lavish charity extended without reference to the needs of those helped; promiscuous blame suggests stupid indifference as to the persons or things one's censure may affect; promiscuous sexual intercourse implies licentious disregard of normal standards of conduct.