Which word signifies an idea that is expressed indirectly?

The word that signifies an idea expressed indirectly is "implicit." Implicit refers to something that is suggested or understood without being directly stated. This term is often used in contexts where the underlying meaning or implication is not overtly declared but is rather inferred from the context or surrounding information. For example, an implicit understanding between friends might mean that they both know something without needing to say it aloud.

In contrast, the other terms refer to more direct forms of communication. "Explicit" describes something that is stated clearly and in detail, leaving no room for ambiguity. "Overt" refers to actions or expressions that are open, observable, and not hidden, while "direct" denotes a straightforward manner of communication without any nuances or subtleties. These terms all emphasize clarity and openness, which contrasts sharply with the indirect nature of "implicit."