Extracurricular is one word.
The word extracurricular comes from the two words " extra & credit ". So since there is only one ful word that is in the word " extracurricular " extra is the root word.
In (proper!) UK English, it's written with a hyphen. I don't know about US English or other variations of English. If you Google it, you'll find all three forms widely used!
It is two words. Writing it as one is acceptable in the UK and is referred to as a "Britishism." But in American grammar, it is always two separate words.
Extracurricular
Two words - "one day".
No profession requires extracurricular activities as part of their training. If they are required, they are not extracurricular.
I recommend class work, as two words.
It is two words.
Two words.
It's two words. :)
It is two separate words.