Lewis & Short

thymĕla, ae, and thymĕlē, ēs, f., = θυμέλη, an elevation in the centre of the orchestra of a Greek theatre, in the form of an altar, upon which stood the leader of the chorus, Sid. Ep. 9, 13; Cod. Th. 8, 7, 21; Inscr. Spon. Miscell. Ant. p. 148.