multus: wordy; cf. Afran. 202 R. multa ac molesta ; Pl. Men. 316 “hominem multum et odiosum” ; Cic. ND 2.46.119 “nolo in stellarum ratione multus vobis videri” .
neque multus: the apparent contradiction (cf. Catul. 64.83) involves an untranslatable play upon the word multus, which is, perhaps, as has been suggested, a colloquial form for molitus, from molere (sensu obscoeno); cf. colere cultus, adolere adultus, etc.
tecum qui descendit: your competitor, sc. in campum, perhaps omitted colloquially; but cf. Hor. Carm. 3.1.10 “hic generosior descendat in campum petitor” , Hor. Ep. 1.20.5 “fuge quo descendere gestis” .
[2] multus et pathicus: contrasted with multus neque multus, the emphasis lying especially upon the conjunctions, while the ambiguous second multus of v. 1 is unveiled by the substitution for it of the brutally plain pathicus; i.e. your competitor is multus (‘wordy’) and yet not mullus (sens. obsc.); but you, Naso, are multus (‘wordy’) and multus, for you are pathicus; in other words, your competitor is foul-mouthed but not foul-lived, while you, Naso, are foul-mouthed and foul-lived.