The headword, perhaps extracted from the quotation given (though Adler deemed it to be from Homer, who has 10 instances), is the aorist indicative active, third person singular of the verb pari/sthmi; see LSJ s.v. and cf. pi 570, pi 571, pi 572.
[1] The first gloss is the aorist indicative middle, third person singular, of the verb gi/gnomai. Hesychius glosses the headword with parege/neto, he/she/it came to be alongside; see LSJ s.v. paragi/gnomai. The second gloss is the aorist indicative active, third person singular, of the verb perie/xw; see LSJ s.v.
[2] The source of the quotation is uncertain. In her critical apparatus, Adler observes that Roos once proposed its attribution to Arrian (apropos of the first four books of the Parthica), citing similar passages in Plutarch (Crassus 27) and Cassius Dio 40.22.4 (Roos, Studia Arrianea, p. 11). Roos also substituted periexome/nwn for periexo/menoi (ibid. p. 11 note). However, neither the Suda's quoted passage nor Roos' minor redaction of it appear among the later collected fragments (Roos, Flavivs Arrianvs).