Oddly, the entry omits the important point in its source (see n.6 below): that the headword is the third person plural of the present imperative active. In fact the imperative forms in -e/twsan (active) and -e/sqwsan (middle), when they first appear, seem colloquial and Attic, rather than non-Attic, as is indicated here; they occur in our extant Attic literature at the time of Euripides, but in inscriptions only after c. 300 BCE. (see Smyth, Greek Grammar §466.3). They are later than the original forms in -o/ntwn and -e/sqwn, but eventually replace them as standard Greek.
For the meanings of the present indicative active of this verb, see tau 1147.
[1] Here are omitted the crucial observation by Choeroboscus (see n. 6 below] that the headword, gloss and examples are all imperatives and the identification of the forms as plurals.
[2] Lit. 'not having the inflexion -m', sc. -mai.
[3] In each of the verbs cited as parallels, the entry gives first the form in -ontwn and then 'instead of' the form in -etwsan. The same happens in the example of the middle voice at the end.
[4] i.e. the middle and passive in -mai.
[5] The point is that, in Attic, the third person plural of the present imperative middle and passive is identical in form with the third person dual of the same imperative.
[6] Based on Georgius Choeroboscus, Prolegomena and scholia to Theodosius' elementary Canons for the conjugation of verbs, p. 235.12-24 (Grammatici Graeci), but omits certain crucial elements, damaging the sense. Where Theodosius illustrates only with forms of tu/ptw, the Suda adds the example of me/lw. The original runs: "In the imperatives coming from the indicative active the Athenians have the third person plural a homophone for the genitive plural of the corresponding participle, e.g. 'strike, let them strike' (instead of the form in -e/twsan), for 'the men who strike' goes 'of those striking' [in the genitive; the same is repeated for the aorist forms of the same verb]. In the imperatives coming from the indicative middle and passive they make the third person plural a homophone for the third person dual, e.g. [with the same example as the Suda]."