Webster’s Revised Unabridged Dictionary · 1913
Biquintile
Bi·quin′tile (bī·kwĭn′tĭl), n. [Pref. bi- + quintile: cf. F. biquintile.] (Astron.) An aspect of the planets when they are distant from each other by twice the fifth part of a great circle — that is, twice 72 degrees.