Origins
The English verb "implicate" traces its origins to the Latin past participle "implicātus," derived from the verb "implicāre," which means "to fold in," "to enfold," "to entangle," or "to involve." This Latin verb itself is a compound formed from the prefix "in-" meaning "in" or "into," and the root verb "plicāre," which means "to fold," "to bend," or "to plait." The root "plicāre" ultimately descends from the Proto-Indo-European root *pleḱ-, which carries the sense of "to plait," "to fold," or "to weave." Thus, the literal image underlying "implicāre" is that of folding one thing into another so closely that the two become inseparable or entangled.
The English word "implicate" entered the language in the 16th century as a learned borrowing directly from Latin. "implicate" is a learned doublet of the verb "imply." Both "implicate" and "imply" derive from the same Latin source "implicāre," but they arrived in English through different routes and at different times. "Imply" came into English earlier, via Old French, undergoing phonological erosion and semantic narrowing, whereas "implicate" was borrowed later, more directly from Latin, preserving a closer connection to the original form and meaning.
The semantic development of "implicate" retains the core notion of involvement or entanglement, especially in contexts of wrongdoing or crime. To "implicate" someone is to show that they are folded into or involved in a particular act, often illicit. This figurative extension from the physical act of folding or entwining to the abstract idea of involvement or association is consistent with the metaphorical potential of the Latin root.
Latin Roots
The root verb "plicāre" generated a substantial family of related Latin verbs, many of which entered English as loanwords, often retaining traces of the original folding metaphor. For example, "explicāre" means "to unfold" or "to explain," literally to "unfold" a matter so it becomes clear. "Applicāre" means "to fold to" or "to apply," suggesting the act of attaching or bringing something into contact. "Complicāre" means "to fold together," giving rise to "complicate," which conveys the idea of intertwining elements to create complexity. "Replicāre," meaning "to fold back," is the source of "replicate," implying a folding back or repeating. "Duplicāre," meaning "to double" or "to fold in two," is the root of "duplicate." Lastly, "supplicāre," meaning "to kneel" or "to bend the knee in prayer," metaphorically involves folding oneself in supplication.
These related verbs illustrate how the metaphor of folding and bending permeated a range of semantic fields in Latin and subsequently in English. The persistence of this metaphor in English loanwords highlights the conceptual link between physical folding and abstract notions such as involvement, complexity, repetition, and submission.
"implicate" is a learned borrowing from Latin "implicātus," the past participle of "implicāre," itself a compound of "in-" and "plicāre," rooted in the Proto-Indo-European *pleḱ-. The word entered English in the 16th century, preserving the original metaphor of folding or entangling, which underlies its modern meanings of showing involvement, especially in wrongdoing, or conveying indirect meaning. It stands as a doublet of "imply," sharing the same Latin origin but differing in route and nuance. The broader family of "plicāre"-derived words in Latin and English further shows the rich semantic field generated by the metaphor of folding.