c.1600, from L.L. soliloquium
"a talking to oneself," from L. solus
"alone" + loqui
"speak." First used in translation of L. "Liber Soliloquiorum,"
a treatise by Augustine, who is said to have coined the word, on analogy of Gk. monologia
). Verb soliloquize
is recorded from 1759.