A depressor consonant is a consonant

Consonant

In articulatory phonetics, a consonant is a speech sound that is articulated with complete or partial closure of the vocal tract. Examples are , pronounced with the lips; , pronounced with the front of the tongue; , pronounced with the back of the tongue; , pronounced in the throat; and ,...

 that depresses (lowers) the tone

Tone (linguistics)

Tone is the use of pitch in language to distinguish lexical or grammatical meaning—that is, to distinguish or inflect words. All verbal languages use pitch to express emotional and other paralinguistic information, and to convey emphasis, contrast, and other such features in what is called...

 of its or a neighboring syllable. This is a consequence of the phonation

Phonation

Phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology...

 (type of voicing) of the consonant. The Nguni languages of South Africa are well known for the lowering effects of certain consonants on tone, as are the Wu dialects of Chinese. Specific examples of these are Zulu and Shanghainese.