- to enlarge in discourse or writing; be copious in description or discussion:to expatiate upon a theme.
- Archaic. to move or wander about intellectually, imaginatively, etc., without restraint.
1530s, "walk about, roam freely," from L. expatiatus, exspatiatus, pp. of expatiari, exspatiari "wander, digress," from ex- "out" + spatiari "to walk, spread out," from spatium (see space). Meaning "talk or write at length" is 1610s.
"When the baron expatiated upon the superior practices of Europe, the Indians were baffled."
- Charles Mann, 1491: New Revelations of the Americas Before Columbus