'Tenebrae' definitions:

Definition of 'Tenebrae'

From: GCIDE

Tenebrae \Ten"e*brae\, n. [L., pl., darkness.] (R. C. Ch.) The matins and lauds for the last three days of Holy Week, commemorating the sufferings and death of Christ, -- usually sung on the afternoon or evening of Wednesday, Thursday, and Friday, instead of on the following days. [1913 Webster]