What is the Latin word for esplanade?

The usual Latin words for “esplanade” are plānus, herbōsus. The right choice depends on the sense; see the distinctions below.

English → Latin

“esplanade” in Latin

plānuslevel, flat, even; intelligible, clear herbōsusgrassy, full of grass or herbs; grass-colored

The English word esplanade itself goes back to Latin plānus, through explānāre.

Riddle & Arnold A Copious and Critical English–Latin Lexicon, 1864

esplanade

“The void space between the glacis and the first houses of the town,” quidquid herbidi terreni est or erat extra murum (Liv. 23, 19, 14, as it usually is a grassy slope); locus aequus: planum (Sall., as levelled space).

Grass-plot, locus herbidus or (Hor.) herbosus.

Quick answer

What is the Latin word for esplanade?: The usual Latin words for “esplanade” are plānus, herbōsus. The right choice depends on the sense; see the distinctions below.

Entry from J. E. Riddle & T. K. Arnold, A Copious and Critical English–Latin Lexicon (rev. C. Anthon, New York: Harper, 1864), digitised by Fergus J. P. Walsh, CC BY-SA 4.0; Latin markup adapted by latindictionary.co.