Even for senses that are truly equivalent in meaning, there are often collocational differences as illustrated in (3–4). “Perfect” synonymy is extremely rare, and some linguists would say that it never occurs. This shows that frightened is a synonym of scared. The two sentences are semantically equivalent (each entails the other). For example, we can change sentence (2a) into sentence (2b) by replacing frightened with scared. As a more rigorous definition, we will say that two words are synonymous (for a specific sense of each word) if substituting one word for the other does not change the meaning of a sentence. We often speak of synonyms as being words that “mean the same thing”. In this chapter we will be primarily concerned with paradigmatic relations. We will consider some syntagmatic relations in Chapter 7, when we discuss selectional restrictions. Look at that big mosquito/elephant/?#surname/#color/*discontinuous/*snore! Look at that big/large/small/enormous/?#discontinuous/*snore mosquito!ī. (In this example we see that big can modify some head nouns but not others.) These relations are referred to as syntagmatic relations. We might also want to investigate relations which hold between words which can occur in construction with each other, as illustrated in (1b). These relations are referred to as paradigmatic sense relations. The kinds of meaning relations mentioned above (same meaning, opposite meaning, etc.) hold between words which are mutually substitutable, i.e., which can occur in the same syntactic environments, as illustrated in (1a). Syntactic relationships are also relevant. The range of useful comparisons seems to be limited by some concept of semantic similarity or comparability. But comparing big with words like multilingual or extradite seems unlikely to be very enlightening. If we are interested in the meaning of the word big, it seems natural to look at its meaning relations with words like large, small, enormous, etc. Let’s begin by thinking about what kinds of meaning relations are likely to be worth studying.