LSJ s.v. μακκοάω ('be stupid') glosses Ar.Eq.62 (εἶτ’ αὐτὸν ὡς ὁρᾷ μεμακκοακότα,) as 'sitting mooning'. The notion of sitting is not explicit in this context, although it is in μακκοᾷ καθήμενος (Eq.396).
OED s.v. moon, v. 2 a-c helps by referring to aimless behaviour and daydreaming - a meaning reported as recently as 1997. However, this gloss could easily misunderstood (OED s.v. moon, v. 4 a) so as to put more smut into Aristophanes.