normally sub- or hypo-
so underground: subterranean
under the skin (dermis): hypodermic
The word below is a preposition. It means in a lower position.
Down means of lower place.
The word underneath means below. under, beneath, lower or downward facing part of a surface
lower
The word that means below the stomach is "hypogastric."
Subnormal means below normal.
Subnormal means below normal.
The word that means "takes place" is "occurs."
under means "lower part" or placed beneath Examples: undermine (under-mine) - means treat as lower, lower in value underestimate - estimate on lower side undergraduate - lower class of graduation
Submandibular comes from sub (below), mandibul (lower jaw) and -ar (suffix meaning pertaining to). The word means beneath the mandible or lower jaw.
"Local" is a word that means specific to a place.
That is what the word means. Superior means above.