from The American Heritage® Dictionary of the English Language, 4th Edition
- adj. Articulated in the same area of the vocal tract, as (t) and (n).
from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of consonants having the same place of articulation. For example, labial m, b, p, alveolar n, d, t, velar ŋ, g, k. The Indic alphabets such as Devanagari are rationally arranged so that homorganic consonants are grouped together.
- adj. produced by the same or homologous organs
from The Century Dictionary and Cyclopedia
- Similarly organized.
- Produced by the same organs.
This word then can serve as a direct source for Latin campus with homorganic nasal resonant -m- added.
Progressive partial homorganic assimilation could easily account for the intrusive b that showed up in later spellings, though the OED does not make such a speculation.