These words refer to things of more than normal size or to things of unusual mass. Large and big are both very general and very vague; both are acceptable in contexts ranging from the most informal to the most formal, although large would tend to be substituted for big in extremely formal contexts. Big suggests something of more than normal size, but it is particularly relevant to material or bodily mass, whereas large might suggest even greater departure from a norm. In this case, the word’s implications are less limited to the physical: a big stone; a big bully; a large house; trying on a larger size shoe; the large issues confronting us.

Outsize (or its variant, outsized ) specifically suggests something that is too large to conform to the norm or be accommodated by an already established measure. While the word thus suggests an object of abnormal or excessive size, unusual mass is not necessarily implied by the word: outsize typing paper that wouldn’t fit the binder in which she kept the other reports; extra-large beds for outsize people. King-size (or its variant, king-sized ) is merchandising term that refers to a product that is longer or larger than the standard or usual size: king-size cigarettes; king-size beds. The use of such terminology in packaging and advertising is very prevalent, probably because it is more deceptive about value than it is informative about size.

Gigantic and mammoth are now mostly used as hyperboles, suggesting anything of extreme proportions. Gigantic derives from a word for giant; mammoth , of course, can refer to the prehistoric elephantlike animal. Mammoth in this context still may more readily suggest something physically big, whereas gigantic is more often used now for metaphorical instances: a mammoth skyscraper; a gigantic threat to our security. But this is by no means invariable: a mammoth weekend party; a gigantic brute of a man.

Giant differs from gigantic in often suggesting a physical change of scale or in referring to something reproduced in outsized dimensions: a science-fiction story about giant cockroaches. As a mere hyperbole, it can be used indiscriminately: a giant protest rally. In this example, reference to a large rally is no doubt intended, rather than to one made up of disgruntled giants .