Lewis & Short

succentor, ōris, m. [succino],

  1. I. an accompanier in singing, Aug. Enarr. in Psa. 87, 1; Isid. 7, 12, 26.
  2. II. Trop., a furtherer, promoter: fabularum, Amm. 19, 12, 13; Isid. Orig. 6, 19, 13.