No, it is - with different wording . It is just that in CS it is defined often as half a byte (4 bits) which is wrong since Leibnitz , not Boole, and even I Ching many moons before that, defined what we now call Boolean arithmatic and both explained the importance of a half value..
If a word is used a certain way, it cannot be wrong. This is the only rule of linguistics, it is always descriptive, never prescriptive. You can say how a word is used, but not how a word should be used.
It's a bit different with respect to scientific definitions in a certain context. For example, as you mentioned boolean arithmetic, the very first definition of my discrete maths class at university was the definition of logical formulas, which included a specific defintion for the terms "boolean constant" and "boolean function". So when I would be in that class and claim that 1 is the boolean constant representing the value "false", I'd be wrong according to the definitions set out earlier in that class. But only in that context because of this definition.
For example in the context of bash scripting, exit codes are used to evaluate logical operations, where 0 means true and any other value represents false. There the defintions of my discrete maths course do not hold, because in this context the definitions made by the POSIX standard are used for describing the properties of the language.
Long story short, the term Nibble is mostly used to describe half-bytes, and this is completely correct in these times. Thats just how language works