Souvenir from a 1968 Broadway musical?

• Garment worn for penance
• Deerstalker perhaps worn by tiddly Irish rector - is he sorry to have put it on?
• Garment of penance
• Penitent's garb

Wiktionary Word definitions in Wiktionary
a. Advocating or adopting a relatively ascetic lifestyle, especially for environmentalist reasons. n. 1 A shirt made of haircloth; a cilice; especially one worn by ascetics or the penitent 2 (cx: figurative) A state of penitence and humility.

Wikipedia Word definitions in Wikipedia
A hairshirt is a cilice , an uncomfortable shirt worn by some Catholics and, earlier, by Jews as a sign of penance. Hairshirt may also refer to: Hairshirt (film) , a 1998 motion picture starring Dean Paras, Chris Hogan, Evan Glenn and Neve Campbell "Hairshirt", ...