Lewis & Short

ŏpertōrĭum, ii, n. [operio].

  1. I. In gen., a cover (post-Aug.), Sen. Ep. 87, 2; Vulg. Exod. 36, 19.
    Trop.: peccati, Ambros. in Psa. 118, Serm. 7, § 31; id. Cant. Cantic. 3, § 2.
  2. II. In partic.
      1. 1. A garment, Vulg. Psa. 101, 27.
      2. 2. A grave (post-class.), Sid. Ep. 3, 12.