Your example is also incorrect because I'll assume you think that a Byte is 8 bits but technically it's not, it's an arrangement of bits a byte can be 0-255bits, it was common to have non 8bit bytes in the past.
The 8 bit byte was set by a specific ISO standard and later by IEEE but it's defined as 8 bits only within those standards.
Agile also has a definition if nothing else because you have bodies and various foundations promoting a specific implementation of it.
"Open Source" has a specific definition that is the one from the OSI.
https://opensource.org/osd-annotated
Any conflicts that exist are not conflicts in the definition of Open Source, but are different definitions for different terms which is why the terms open-source software and free and open-source software exist.
This isn't a subjective matter, this is a very well defined term, if nothing else because OSS and FOSS software is used in the industry including in commercial products this requires the definitions and the licenses to be very very specific to meet legal and regulatory requirements.
So while you can say there are different software licenses to meet the requirements of being Open Source it needs to meet the definitions set by the OSI which are in general mean that the source code must be available, that the distribution is not restricted in any way which usually means that it's distributed under a free and non-discriminatory license agreement.
You may chose not the follow this definition but this doesn't mean that this is a correct action, this is no more subjective than the definition of a kilogram. Definitions exist for a reason and that is to remove ambiguity, if ambiguity exists its either because there is no definition or consensus which is clearly not the case with Open Source Software.
Emphasis mine.