magnetohydrodynamics

This term describes a specialized branch of physics that merges fluid dynamics and electromagnetism. It is used almost exclusively in academic, scientific, and engineering registers, particularly within astrophysics and plasma physics. Because it refers to a field of study, it functions as a mass noun.

As a discipline name ending in -ics, it follows the pattern of words like physics or mathematics. While it describes a collection of theories and laws, it is treated as a singular uncountable noun and does not have a plural form.