#apropo

• By the way — An adverb used to spontaneously introduce a remark, memory, or digression directly or indirectly related to the topic under discussion; as a neuter noun, it designates a subtle allusion, an incidental remark, a fine irony, or an indirect suggestion made within a conversation.
• Propontis — A historical and archaic literary designation attributed to the Sea of Marmara, used primarily in medieval charters and Romanian Byzantine chronicles to indicate the structural water basin located between the Bosphorus and Dardanelles straits, connecting the Pontus Euxinus to the Aegean Sea.
• By the way — An etymological graphic variant for the noun and adverb 'apropo'; a subtle allusion, passing remark, or indirect suggestion made within a dialogue. As an adverb, it is used to spontaneously introduce a digression or memory structurally linked to the current topic.
• Passing remark — A fully adapted phonetic spelling variant of the neuter noun 'apropo'; a subtle allusion, passing remark, or indirect suggestion made within a conversation to convey a hidden message, fine irony, or unstated desire.
• Apropos — A very rare, learned, or archaic form borrowed from Italian, used in pre-modern texts as a structural equivalent for 'by the way' or 'opportunely'; it serves to introduce an incidental remark or indicates that an action happens exactly at the right moment.