The Collaborative International Dictionary
Biquintile
Biquintile \Bi*quin"tile\, 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.
Wiktionary
biquintile
n. (context astrology English) An aspect of two planets that are distant from each other by two fifths of a great circle (72 degrees)