Both Uses

demeanor
in
Rappaccini's Daughter
(Auto-generated)

On the contrary, he avoided their actual touch or the direct inhaling of their odors with a caution that impressed Giovanni most disagreeably; for the man's demeanor was that of one walking among malignant influences, such as savage beasts, or deadly snakes, or evil spirits, which, should he allow them one moment of license, would wreak upon him some terrible fatality.†
But, with all this intimate familiarity, there was still a reserve in Beatrice's demeanor, so rigidly and invariably sustained that the idea of infringing it scarcely occurred to his imagination.†
*

Definitions:

(1) (demeanor)
the manner in which a person behaves
(2) (meaning too rare to warrant focus)
Much more rarely, the verb form may be used as a synonym for behave as in: "Try to demean yourself with dignity."