Sacred Garments
Thiruparivattam (Tamil: tiru = sacred + parivattam = covering/garment; Sanskrit parivāsa = covering; 'sacred covering/vestments') refers to the garments worn by the deity, offered to the deity, or worn by Ācāryas. When clothing has been in contact with the sacred, it becomes prasādam — receiving the Ācārya's or deity's thiruparivattam as prasādam is a profound blessing.
Temple Garments
In major Divya Deśams, the deity is adorned with elaborate alaṃkāram (ornamentation) including silk garments, jewels, and flower garlands at each worship service. The garments removed from the deity at the close of worship are distributed to senior devotees as thiruparivattam prasādam. Receiving such a garment — touched by the deity's form — is considered equivalent to receiving the deity's direct blessing.
Uthariyam
Uthariyam (from Sanskrit uttarīya = upper garment, shawl) is a related term referring specifically to the upper cloth or shawl — used respectfully for the shawl worn by an Ācārya or offered to the deity. Receiving an Ācārya's uthariyam as prasādam is a mark of his specific grace toward the recipient.