I'll give OP the benefit of the doubt and assume that he is just making a semantic error, not the much more egregious error others are making in this thread of calling anything aikido in which they find the principles of aikido. But it's still a semantic error that needs to be corrected, since the word in question is aikido itself.
It's a semantic error only according to your definition
. According to other's definitions that may not be the case - in fact, according to other definitions calling what you do in the dojo with the funny clothes on may well be a semantic error.
And no, linguistically a word doesn't have to be that tightly defined to have meaning or to be usable (take "love" for example, which is enourmously vague and variable) - it just means that further qualifiers would be necessary to clarify what you're talking about. Thus, for example, Stan Pranin talks about "modern" Aikido.