In a tearful statement, he launched into a soliloquy about seeing himself free again playing with children, balloons, and dogs.
I also read, relatedly, John Galt's soliloquy for the first time in my life the other day.
Biden launched into a soliloquy in praise of double-barrel shotguns.
1610s, from Late Latin soliloquium "a talking to oneself," from Latin solus "alone" (see sole (adj.)) + loqui "speak" (see locution). Also used in translation of Latin "Liber Soliloquiorum," a treatise by Augustine, who is said to have coined the word, on analogy of Greek monologia (see monologue). Related: Soliloquent.