The headword, here nominative plural glossed as feminine, is a frequent epithet applied to women in epic poetry. See e.g. Homer, Iliad 6.442 (web address 1).
Information similar to various parts of this entry is found in Hesychius (epsilon2131), Lexica Segueriana 216.17 Bachmann, Etymologicum Magnum 334 and 74, and Etymologicum Genuinum alpha559, and the scholia to Homer loc.cit., though none seems to be the direct source for the Suda.
For robes cf. pi 1005, pi 1006.
[1] This list consists of: 1) the first person singular present indicative active of the verb that provides the first element of the compound ('drag'); 2) and 3) two unattested and probably hypothetical forms of the compound 'robe-dragging', illustrating the transition described in the first sentence; and 4) the final product of the transition, namely the headword (in the nominative singular masculine or feminine). The following two lists illustrate parallel (hypothetical) developments (see following notes). The etymology described here are attributed to Methodios in Etymologicum Magnum 73.
[2] This sequence illustrates how one gets from prw=tos ('first') to the anthroponym *prwtesi/laos through two unattested, and probably hypothetical, intermediary forms.
[3] From phgo/s ('thick') to phgesi/mallos ('thick-fleeced') through two unattested, and probably hypothetical, intermediary forms.
[4] These two series illustrate an alternative explanation (one that is closer to the modern explanation) for the etymology of both e(lkesi/peplos and phgesi/mallos: the 'future' stem (modern linguists would more likely designate this the aorist stem but it amounts to the same thing for these verbs) of the two verbs e(lc- and phc- (= e(lk-s and phk-s respectively) have an 'e' inserted into the final consonant cluster of the stem, yielding e(lkes- and phkes-. A modern commentator would add that this addition is probably for metrical reasons, since without it neither word would fit in a dactylic hexameter. Chantraine cites e(lkesi/peplos as a possible instance of metrical shortening: cf. e(lkhsi/staxus with an eta in an oracle quoted by Pausanias (8.42.6, s.v.l.; also in Anthologia Graeca Appendix, Oracula 54.6).