Likewise or similarly in other lexica; references at Photius omicron312 Theodoridis.
For the derivation of the headword (also under chi 370), see generally spondh/ at sigma 958. Its inclusion in the lexica was probably, as Latte on Hesychius omicron804 suggests, generated by its occurrence in Demosthenes 18.287 (for which cf. omicron 282).