These words are comparable in that they are all used to designate a kind of dog and, in a pejorative way, a kind of person. A mongrel is any animal or plant of mixed breed, but especially a dog. Since there is a strong suggestion of illegitimacy about a mongrel (often shortened to mong ), such a dog is often looked down upon by dog fanciers. It may, indeed, be this somewhat contemptuous feeling for mongrel dogs which has given the pejorative connotation to mongrel when it denotes a person who is not of a pure race, whose parents are of different national or social back grounds, or one whose tendencies, political opinions, religious convictions, etc., are undefined or uncertain.

• Ever since that "independent" member was elected, the only consistency about him has been his inconsistency; the man has proved himself to be a political mongrel .

In reference to a man, mongrel also means one who is despicable on account of cruelly inconsiderate behaviour. Cur , in its denotation of a dog, is synonymous with mongrel . But whereas a mongrel , in spite of its questionable ancestry, can be looked on as a worthwhile pet, a cur is despised by the dog lover as an inferior, ugly or unfriendly beast. The same feeling reserved for this cur greets the mean, malicious, cowardly or otherwise objectionable person who is described by the same name: a man with pretensions to honour and bravery who proves himself a cur in the face of the slightest danger. The mainly American word mutt , when it designates a dog, is synonymous with mongrel and cur , but, even more than is true with mongrel , mutt frequently refers to a loved pet rather than to one that is thought to be worthless. A person who is a mutt is stupid or doltish. Although such a person is not held in high esteem, he is usually not treated with the contempt or disdain accorded one called mongrel or cur . One might, in fact, feel the same kind of affection for the human mutt that is shown for the less than pedigreed dog.

Hound , like the other words in this group, is general in its designation of a dog of any breed or background. It can be specific in a way the other words cannot, when it refers to any of several breeds of hunting dog. When hound denotes a person it may characterize someone who is detestable in the way that a mongrel or cur is. But it may also refer, in an informal way, to a person who is fond to the point of addiction of a certain pastime, activity, food, etc.: a bridge hound ; a hot-pie hound .