Based on your question, I would recommend posting some of the example sentences where you have seen this word.
the below is a copy paste (credit Dictionary.com) of the variety of uses. I also see it now has a use in "urban slang" - see point 5.
1 - having a specified object or material as its base or foundation or as its primary constituent (often used in combination):
Our house was one of the three stone-based houses of that era, built by my maternal grandfather.
2 - established, grounded, or focused on a specified principle or belief, fact, method, etc. (often used in combination):
It’s a culturally based phys ed curriculum that uses Indian traditions and values to teach healthy lifestyle habits.
There are a number of promising evidence-based treatment modalities to address depression.
3 - having a specified place as its primary location or headquarters; stationed or situated (often used in combination):
A centrally based Houston media agency is looking for a Digital Account Manager to help with a key communications client.
The Chicago-based HIV/AIDS organization provides housing, healthcare, and substance abuse programs for its clients.
4 - having a specified origin or source (often used in combination):
They want to replace animal-based foods with plant-based milks and vegetable protein.
5 - Slang. true to one’s self or secure in one’s beliefs regardless of what others think, especially when those beliefs fall outside of the mainstream:
Her presentation was so based—did you see the teacher's expression? Priceless!