ETYM Latin soliloquium; solus alone + loqui to speak. Related to Sole ly, and Loquacious.
1. A (usually long) dramatic speech intended to give the illusion of unspoken reflections.
2. Speech one makes to oneself; SYN. monologue.
In drama, thinking aloud. A soliloquy is a speech for the benefit of the audience only and by convention is not heard by any other actor on stage at the time.