Variantly: "Chiroth" connotes the place of their (Israel's) freedom ("cheruthan"), a choice place for them (the Egyptians), the place of their idolatry. In the past it was called Pithom, viz. (Exodus 1:11) "And it (Israel) built treasure cities for Pharaoh, Pithom and Ramses." They (the Egyptians) stopped (calling it Pithom) and called it Pi Chachiroth because it disappointed ("me'achereth" [lit., "delayed"]) its worshippers (by not stopping Israel from escaping).
Chiroth Connotes the Place of Their Israel's
Mekhilta Tractate Vayehi Beshalach 2:2