A word for unacustomedness / dishabitude?

Question

I'm looking for a contrary to the word habitude. I found dishabitude which has a very specific meaning in psychology literature, so it applies only to psychology jargon and not to everyday speech.

Is there a one-word term to express the general concept of "being unaccustomed to"?

Answer 1

A sensible choice is ​unfamiliarity.

​unfamiliarity (with something) the fact of having no knowledge or experience of something

• He admits his relative unfamiliarity with this literature.

Oxford Learners Dictionaries

• There are weaknesses that suggest the author's unfamiliarity with standard academic practices.

Cambridge English Corpus

And an example showing a less academic, more social application: (bolding mine)

What is Culture Shock?

Culture shock is the feeling of disorientation experienced by someone when they are suddenly subjected to an unfamiliar culture and way of life. It can be caused by a range of things, both big and small, such as unfamiliar greetings and hand gestures, strange food, difficult language barriers, getting lost in a new city or making a cultural faux pas because you didn’t know the local custom.

This unfamiliarity can lead to symptoms such as confusion, anxiety, frustration, loneliness, and homesickness.

Now-Health.com

Answer 2

You could try desuetude:

desuetude n
the state of being no longer used or practiced.
_{TFD Online (Random House)}