/ ˌfʌndəˈmentəli; NAmE / adverb
1.
in every way that is important; completely :
The two approaches are fundamentally different.
By the 1960s the situation had changed fundamentally.
They remained fundamentally opposed to the plan.
2.
used when you are introducing a topic and stating sth important about it
SYN basically :
Fundamentally, there are two different approaches to the problem.
3.
used when you are saying what is the most important thing about sb/sth
SYN basically :
She is fundamentally a nice person, but she finds it difficult to communicate.