Sinis in Greek and Roman Biography and Mythology
or SINNIS (Σίνις or Σιννις), a son of Polypemon, Pemon or
Poseidon by Sylea, the daughter of Corinthus. He was surnamed
according to some Pityocamptes, and according to others
Procrustes. He dwelt on the isthmus of Corinth as a robber,
destroying the travellers whom he had conquered, by fastening
them to the top of a fir-tree, which he curbed, and then let
spring up .gain. He himself was killed in this manner by
Theseus (Apollod. 3.16.2; Plut. Thes. 8; Paus. 2.1.3, &c.;
Diod. 4.59 ; Eur. Hipp. 977; Ov. Met. 7.440, &c. ; Hyg. Fab.
38; Schol. Pind. Hypoth. Isthm.). When Theseus had
accomplished this, he caused himself to be purified by
Phytalus at the altar of Zeus Meilichios, because Theseus
himself was related to Sinis (Paus. 1.37.3), or according to
others, he propitiated the spirit of Sinis by instituting in
his honour the Isthmian games (Schol. Pind. l.c. ; Plut. Thes.
25; Welcker, Nachtrag, p. 133). The name is connected with
σίνομαι, expressing the manner in which he tore his victims to
pieces. - A Dictionary of Greek and Roman biography and
mythology, William Smith, Ed.