Latin vocative from of Tereus, who "rudely forc'd" Philomela; it was also one of the conventional words for a nightingale's song in Elizabethan poetry. Cf. the song from John Lyly's Alexander and Campaspe (1564):

Oh, 'tis the ravished nightingale.
Jug, jug, jug, jug, tereu! she cries,"

and lines 100ff. (NA)

reference topics

John Lyly's Alexander and Campaspe
Ovid's Metamorphoses, The Story of Tereus, Procne and Philomela
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