Lewis & Short

mortŭālĭa, ĭum, n. [mortuus].

  1. I. (Sc. vestimenta.) Grave-clothes or mourningweeds (ante-class.), Naev. ap. Non. 548, 28 (Trag. Rel. v. 48 Rib.).
  2. II. (Sc. carmina.) Haec sunt non nugae; non enim mortualia, funeral songs, dirges, referring to the custom at Rome of hiring women to sing absurd eulogies of the dead at funerals, Plaut. As. 4, 1, 63.