The headword is a rare adjective, which in a concrete sense is used of horses. See e.g. Xenophon, On Horsemanship 3.10, and Aelius Dionysius *peri\ o)no/mata omicron27, quoting Aristophanes fr. 43 Kock = 44 K.-A.; see at omicron 577.
This entry is considered by Adler to be excerpted from the Synagoge: although it does not occur in the editions of Bachmann or Cunningham, there is a very similar entry in Photius, Lexicon delta804, and Etymologicum Genuinum s.v. (cf. Etymologicum Magnum 291.47).
For the etymological expansion of the gloss cf. generally gamma 62, gamma 63 (and further in n.2 below).
[1] An adjective even rarer than the headword itself; dusupo/taktos is not in LSJ and is found (outside lexicography) only in astrological texts describing the characteristics of Leo. Hesychius delta2540 has different glossing: duspra/untos, ou)x u(potasso/menos.
[2] This meaning oocurs in Byzantine lexicographic texts: besides the Suda see Photius delta804 and Etymologicum Magnum 291.47, where this same gloss is quoted from somewhere. On the other hand, in Timaeus, Platonic Lexicon gamma981, we have: gargali/zei: kinei=, u(poshmai/nei, protre/pei, e)rei/zei; 'gargali/zei[third person singular]: sets in motion, indicates [in an abstract sense], urges on, excites' (cf. gamma 63), while in Hesychius gamma303 this verb is used to gloss another one, gelli/zein, which is unattested in writers and with no clear meaning. If we take into account gaggali/zw, considered by LSJ s.v. a modification of gargali/zw, whose use was criticised by Phrynichus (Eclogae 68), in Orion [Author, Myth] Grammaticus (fifth century AD), Etymologicum Magnum gamma41, quoting Philoxenus Grammaticus, we have: 'gaggali/zw [first person singular], I move to laughter', this could explain the second part of our gloss.