Meaning (linguistic) in the context of "Idiom"

In linguistics, function words (also called functors) are words that have little lexical meaning or have ambiguous meaning and express grammatical relationships among other words within a sentence, or specify the attitude or mood of the speaker. They signal the structural relationships that words have to one another and are the glue that holds sentences together. Thus they form important elements in the structures of sentences.

Words that are not function words are called content words (or open class words, lexical words, or autosemantic words) and include nouns, most verbs, adjectives, and most adverbs, although some adverbs are function words (like then and why). Dictionaries define the specific meanings of content words but can describe only the general usages of function words. By contrast, grammars describe the use of function words in detail but treat lexical words only in general terms.

In logic, extensional and intensional definitions are two key ways in which the objects, concepts, or referents a term refers to can be defined. They give meaning or denotation to a term.An intensional definition gives meaning to a term by specifying necessary and sufficient conditions for when the term should be used. An extensional definition gives meaning to a term by specifying every object that falls under the definition of the term in question.

For example, in set theory one would extensionally define the set of square numbers as {0, 1, 4, 9, 16, ${\displaystyle \dots }$}, while an intensional definition of the set of the square numbers could be {${\displaystyle x\mid x}$ is the square of an integer}.

An ostensive definition conveys the meaning of a term by pointing out examples. This type of definition is often used where the term is difficult to define verbally, either because the words will not be understood (as with children and new speakers of a language) or because of the nature of the term (such as colors or sensations). It is usually accompanied with a gesture pointing to the object serving as an example, and for this reason is also often referred to as "definition by pointing".