{ } a. [ Ortho- + Gr. &unr_; to turn: cf. F. orthotrope. ] (Bot.) Having the axis of an ovule or seed straight from the hilum and chalaza to the orifice or the micropyle; atropous. [ 1913 Webster ]

☞ This word has also been used (but improperly) to describe any embryo whose radicle points towards, or is next to, the hilum. [ 1913 Webster ]