The headword is the aorist subjunctive middle, first person singular, of the verb proi/hmi, I send beforehand, let go; see generally LSJ s.v. It is taken to be quoted from Job 27.6 LXX (accented prow=mai there), where Job avers dikaiosu/nh| de\ prose/xwn ou) mh\ prow=mai (But holding closely to righteousness, I would not let go [sc. of my guilelessness]); cf. Hesychius omicron1778 (s.v. ou) mh\ pro/wmai) and ps.-Zonaras 1486.6, with glossing verb identical to this entry's but negated as in Job.
[1] The gloss is the aorist subjunctive active, first person singular, of the verb paraxwre/w, I go aside, make way for; see generally LSJ s.v. The headword is identically glossed in the Synagoge, Photius' Lexicon (pi1431 Theodoridis), and Lexica Segueriana 353.22; cf. the first person plural forms at Bekker 288.15.