transitive. To relate, describe, or set forth at length; to enlarge or expatiate upon. Obsolete.

To enlarge (a story or statement) by telling it more diffusely or fully, or by adding fresh details, illustrations, or reflections; to expand…

intransitive. To comment on, enlarge upon a subject. Also figurative. Obsolete.

To put or bring forward in argument or the like; to expound; to make patent; to expose. Also reflexive to expatiate upon.

To stretch out in a prostrate position; to bring out and display openly.

To develop (views).