Which term best describes a multiword expression for which meaning cannot be directly determined from context?

The term that best describes a multiword expression for which meaning cannot be directly determined from context is "idiom." Idioms are phrases whose meanings are not deducible from the individual words that compose them. For example, the idiomatic expression "kick the bucket" means to die, which is not evident when analyzing the words separately.

In contrast, denotation refers to the literal meaning of a word, and connotation involves the implied or associated meanings that a word carries beyond its literal definition. Technical words pertain to specialized vocabulary used within a particular field or profession, often having precise meanings that may not be understood outside that context. None of these terms capture the nuanced, figurative nature of idioms, which rely on cultural understanding rather than straightforward interpretation of the words.