From a (as a negative particle) and a presumed derivative of the same as rhaphis; unsewed, i.e. Of a single piece -- without seam.
see GREEK a
see GREEK rhaphis
STRONGS NT 729: ἄρραφοςἄρραφος, T Tr WH ἄραφος (cf. Winers Grammar, 48; Buttmann, 32 (29); (WHs Appendix, p. 163; Tdf. Proleg., p. 80; cf. Rho)), ἀρραφον (ῤάπτω to sew together), not sewed together, without a seam: John 19:23.