Is it really ok to speak about compling and interpreted languages?

It is quite obvious that any interpreted language MAY also be compiled. For a long time, I thought it was not necessarily the opposite. Then I discovered Ch, an interpreter able to interpret the C language as a whole. It also supports parts of C ++, Java, Matlab, Fortran and C-shell.

This led me to conclude that the fact that a language is a compiled or interpreted language is not a property of the language itself but rather a convention. Is it correct?