The Only Use of

inferior
in
To Kill a Mockingbird

The most ridiculous example I can think of is that the people who run public education promote the stupid and idle along with the industrious— because all men are created equal, educators will gravely tell you, the children left behind suffer terrible feelings of inferiority.†
p. 233.3

inferiority = the state of being of low quality or of lower quality than something else

Definitions:

(1) (inferior)
of low quality, or of lower quality or rank than something else -- sometimes used as a noun to refer to a person of lower rank or status
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, specialized senses include:
- anatomy and botany -- a lower position on a body or plant (or pointed downward)
- typography -- a character that drops beneath a printing line (such as with subscript)
- astronomy -- having an orbit relative to the sun that is lower than earth's (making Mercury and Venus inferior planets)