The compound adjective 'wide-mouthed' is a straightforward combination of native English elements. The first element, 'wide', traces back to the Proto-Germanic wīdaz, conveying the sense of being far-spread or broad. The second, 'mouth', originates from Proto-Germanic munþaz, referring literally to the oral cavity but also metaphorically to any opening or entrance. The suffix '-ed', used to form adjectives from nouns, indicates possession of the specified feature. The term's logic is transparently literal, describing an entity—be it a living creature or a container—that possesses a broad or large opening, with the metaphorical extension to jars or vessels being a natural semantic development.

Structure: wide (broad) + mouth (oral opening) + ed (having the quality of) - wide: From Old English wīd (spacious, extensive), of Germanic origin. Functions as an adjective describing breadth. - mouth: From Old English mūþ (oral opening, entrance), of Germanic origin. Functions as a noun, here used in a compound. - ed: From Old English -ede, an adjectival suffix meaning "having, provided with." Functions as a suffix forming participial adjectives.