Webster’s Revised Unabridged Dictionary · 1913
Expatiate
Ex·pa′ti·ate (ĕks·pā′shĭ·āt), v. i. [imp. & p. p. Expatiated; p. pr. & vb. n. Expariating.] [L. expatiatus, exspatiatus, p. p. of expatiari, exspatiari, to expatiate; ex out + spatiari to walk about spread out, fr. spatium space. See Space.] 1. To range at large, or without restraint.
Bids his free soul expatiate in the skies. Pope.
2. To enlarge in discourse or writing; to be copious in argument or discussion; to descant.
He expatiated on the inconveniences of trade. Addison.
Ex·pa′ti·ate, v. t. To expand; to spread; to extend; to diffuse; to broaden.
Afford art an ample field in which to expatiate itself. Dryden.