particle
Archaic sentence-ending particle expressing a wish or hope. Attaches to nouns, adjectives, or verbs in classical Japanese. In modern Japanese, it appears mainly in literary or poetic contexts, or in set phrases like 言わずもがな.
「言わずもがな」は、言わないほうがよいという意味の慣用句です。
The phrase 言わずもがな is an idiom meaning 'it is better left unsaid'.
古典では「花もがな」のように願望を表す。
In classical texts, もがな expresses a wish, as in 花もがな ('I wish there were flowers').