The headword is an adjective is the masculine and neuter dative plural; see LSJ s.v. stroggu/los, round, spherical, but metaphorically well-rounded, terse, compact. The entry is generated from an instance of the headword in the quotation twice given; see notes below.
[1] The initial gloss anticipates a phrase from the quotation later given in full. [In her critical apparatus Adler reports that mss GFM here do not repeat the headword.] The other glossing adjectives are the same form as the lemma, but from, respectively, the adjectives piqano/s (persuasive, plausible; cf. pi 1572 and pi 1574) and pa/nourgos (ready for anything, wicked, crafty, cunning; cf. pi 212); see LSJ s.vv. and the scholia vetera to the quotation.
[2] Aristophanes, Acharnians 686 (web address 1), already at pi 874. The Chorus-Leader protests what might well be an old man's courtroom predicament.