Source : Webster's Revised Unabridged Dictionary (1913)

Monopteral \Mo*nop"ter*al\, a. [Gr. ? with a row of pillars
   only; mo`nos alone, only + ? feather, wing, also, a row of
   pillars: cf. F. monopt[`e]re.] (Arch.)
   Round and without a cella; consisting of a single ring of
   columns supporting a roof; -- said esp. of a temple.

Source : WordNet®

monopteral
     adj : having circular columniation