verb (used without object), expatiated, expatiating.
1. to enlarge in discourse or writing; be copious in description or discussion: to expatiate upon a theme.
2. Archaic. to move or wander about intellectually, imaginatively, etc., without restraint.
Origin: 1530-40; < Latin expatiātus past participle of ex (s) patiārī to wander, digress, equivalent to ex- ex-+ spatiārī to walk about, derivative of spatium space; see -ate
Now YOU come up with a sentence (or fic? or graphic?) that best illustrates the word.