Lewis & Short

amplĭfĭcātor, ōris, m. [amplifico], he who enlarges, an amplifier (very rare): rerum, Cic. Tusc. 5, 4, 10: MVNICIPII, Inscr. Orell. 1025: VRBIS ROMAE, Inscr. Grut. 282, 3.
Trop.: dignitatis, Cic. Fam. 10, 12.