Webster's Revised Unabridged Dictionary · 1913

Champaign

Champaign , noun

[Old French champaigne; same word as campagne.]

A flat, open country.
Fair champaign, with less rivers interveined. — Milton
Through Apline vale or champaign wide. — Wordsworth

Champaign , adjective

Flat; open; level.
A wide, champaign country, filled with herds. — Addison