These words are used to characterize a collection or group of things or people that are not all alike, or are used to describe a mass made up of different elements. Heterogeneous emphasizes most strongly the differences among individuals or elements closely connected but not necessarily unified.

• New York City has a heterogeneous population; The former tenants had left behind a heterogeneous pile of rubbish; Porphyry is a heterogeneous rock.

Miscellaneous emphasizes diversity arising from lack of any unifying principle in selections and suggests things that have been brought together casually or by chance.

• A small boy’s pockets are likely to contain a miscellaneous collection of objects; a politician who was on a first-name basis with hundreds of miscellaneous people.

Mixed , as considered here, is often used interchangeably with the other words discussed. Specifically it suggests dissimilarity among elements or individuals in a group or mass, but seldom a diversity as extreme or fortuitous as that suggested by miscellaneous .

• When you buy a tin of mixed nuts, you get walnuts, cashews, Brazil nuts, almonds and Barcelona nuts; A mixed social gathering is made up of people of both sexes.

Motley means literally having a variety of colours, but in this context, it describes persons or things that are strongly contrasted or even discordant. Unlike heterogeneous , miscellaneous and mixed , motley has a derogatory connotation.

• Accidents always draw a motley crowd of onlookers; Being self-educated, he has read indiscriminately and absorbed a motley set of conflicting facts and concepts.