Homorganic consonants (from homo- "same" and organ "(speech) organ") is a phonetics term for consonant sounds that are articulated in the same position or place of articulation in the mouth, such as [m], [p], [b] (pronounced with both lips), or [t], [d], [s], [z], [n], [l] (pronounced by touching the tip of the tongue to the upper gums). Consonants that are not articulated in the same place are called heterorganic.
Descriptive phonetic classification relies on the relationships between a number of technical terms that describe the way sounds are made; and one of the relevant elements involves that place at which a specific sound is formed and voiced. In articulatory phonetics, the specific "place of articulation" or "point of articulation" of a consonant is that point of contact, where an obstruction occurs in the vocal tract between an active (moving) articulator (typically some part of the tongue) and a passive (stationary) articulator (typically some part of the roof of the mouth). Along with the manner of articulation and phonation, this gives the consonant its distinctive sound.
Consonants that have a similar or the same place of articulation, such as the alveolar sounds (n, t, d, s, z, l) in English, are said to be homorganic.
A homorganic nasal rule is a case in which the point of articulation of the initial sound is assimilated by the last sound in a prefix. An example of this rule is found in the Yoruba language, where ba, "meet", becomes mba, "is meeting", while sun, "sleep", becomes nsun, "is sleeping".
Two or more consonant sounds may appear sequentially linked or clustered as either identical consonants or homorganic consonants that differ slightly in the manner of articulation, as when the first consonant is a fricative and the second is a stop.