6.2.1 Lexical Semantics, from Sarah Harmon
Catherine Anderson does a really great job of setting up lexical semantics, but there's a few more pieces that I want to cover. One has to do with these connections between reference, so the lexicon or phrase, and the meaning they are associated with.
Almost assuredly you have heard of synonyms before. They are the quintessential proof that language is arbitrary, because if you have similar or same terms for the similar terms for the same meaning, that's arbitrariness.
Antonyms, you almost assuredly have heard of them before. There are three different kinds of antonymy: complimentary, gradable, and relational. Complimentary antonyms are this or that: on/off, alive/dead (sorry, zombie fans, there's nothing in between!). Gradable antonyms are the opposite; they are along a gradation or scale: hot/cold but that there is a whole bunch of other temperatures in between. Relational antonymy does have to do with some kind of relationship: employer/employee, parent/child, teacher/student.
Homophones; you may have heard them as homonyms before. Homophones is what we say in linguistics. They have the same sound, but two completely unrelated backgrounds or origins. In morphology I talked about this before, when I talked about the word bank; that lexicon has two different entries and they're unrelated. One is the financial institution, and the other is the side of a river. Seal, is another one, whether you're talking about the animal or the thing you use to close a document or paper. That is a homophone because they have two completely different meanings and they're completely different origins.
There's three more than I want to go through that you may have heard of before, but maybe not. The first is polysemy. Polysemy is different than homophony; remember homophony has to do with different origins. Polysemy, as the name implies, means they have the same origin just multiple levels of meaning. poly- = multiple, -semy = meaning. If I say the English term sheet, you think of something flat of something thin and flexible or pliable. A sheet of paper; a sheet of linen.
A hypernym is a greater subset. Instead of talking about a specific aspect of something like a red, blue, pink, or purple thing, you talk about a color: ‘oh it's got a lot of color’. That's a hyponym. Instead of talking about a tiger, lion, cheetah, leopard, lynx, or bobcat, you talk about felines. That's a hyponym.
A metonym is a word substitute. Instead of talking about the King of Spain or the Queen of England, you talk about the Spanish crown, the English crown; that term crown is a metonym. Instead of talking about the action during the baseball game, you say the action on the diamond. That is a metonym because the diamond is the shape of the infield of a baseball field.
All six of these areas include some aspect of compositionality, but especially arbitrariness. Whether it's the actual origin or the usage in any given moment, when you're using these six lexical semantic categories, you're talking about arbitrariness, the arbitrary combination of the term, and the meaning.