Pronunciation: [ suh-lil-uh-kwee ]
Definition: noun
an utterance or discourse by a person who is talking to himself or herself or is disregardful of or oblivious to any hearers present

Origin: Middle English; Latin
Etymology: from late Latin soliloquium, from Latin solus ‘alone’ + loqui ‘speak’
Usage:

Synonyms:
discourse
monologue
speech
Antonyms:
dialogue
Example:
Her teenage daughter's soliloquy was both dramatic and seemingly never-ending.