The Collaborative International Dictionary
Semiquartile
Semiquadrate \Sem"i*quad`rate\ (s[e^]m"[i^]*kw[o^]d`r[asl]t),
Semiquartile \Sem"i*quar`tile\ (s[e^]m"[i^]*kw[add]r`t[i^]l), n.
(Astrol.)
An aspect of the planets when distant from each other the
half of a quadrant, or forty-five degrees, or one sign and a
half.
--Hutton.
Wiktionary
semiquartile
n. (context astrology English) A semiquadrate.