The headword is the aorist indicative active, third person singular, of the verb parasfa/llw; cf. Lexica Segueriana 332.24, and see generally LSJ s.v. The headword is quoted from Homer, Iliad 8.311 (web address 1), where Apollo deflects Teucer's arrow. As warranted by meter, in this verse Homer writes pare/sfhlen, so that the final epsilon is long by position (Smyth, 135, 144). Retaining the poet's movable nu, the headword is similarly glossed in Hesychius and Photius.
[1] The first of these (odd) glosses -- paralleled in other lexica, and in the scholia to Homer loc.cit. -- is present indicative middle/passive, third person singular, of the compound verb paremfai/nw; see LSJ s.v. The second gloss is aorist indicative passive, third person singular, of the verb sfa/llw; see LSJ s.v. The third gloss is aorist indicative passive, third person singular, of the verb a)porre/w (see LSJ s.v.), compounding a)po/ and r(e/w, I stream away from.