[1] The headword as transmitted seems to be genitive singular of siso/h (a Phaselite word according to Hesychius), and, if so, quoted from somewhere; however, the gloss is nominative or accusative; and the accusative siso/hn famously occurs at Leviticus 19.27 LXX (see next note). Possibly, then, the Suda's headword is the proper name Sisoes (from a separate entry), and the nominative singular siso/h has dropped out from this entry; more probably [in DW's opinion at least] it is simply a slip for siso/hn.
[2] cf. Leviticus 19.27 LXX, where instructions are given against braiding the hair and trimming the beard.