I.an undertaking, engagement, promise, Hom., Hdt., attic; ὑπ. ἀπολαβεῖν to receive the fulfilment of a promise, Xen.; ἀπαιτεῖν τὰς ὑπ. to demand their fulfilment, Arist.; ὑπ. ψεύδεσθαι to fail in its performance, Aeschin.
II.a profession (as a mode of life), Luc.