I still think the meanings of these words are clear, but perhaps that's because I have come to understand and accept the moral validity of the philosophy. I guess my familiarity with the concepts, may make it difficult for me to recognize the possibility of ambiguous understanding of the terms on the part of others. More often than not though, it has been my experience that these terms are intentionally misinterpreted by individuals wishing to confound discussion of concepts they do not wish to consider. I don't believe this applies in your case.
But for the record, when we discuss force, we are talking about physical force... (or the threat of physical force by logical extension).
When we talk about fraud, we talk about the intentional manipulation of the truth.
Libertarian philosophy prohibits the initiation of physical force (including the threat of physical force), and also prohibits fraud.
Libertarian philosophy prohibits these things, because it recognizes the notion of rights. Rights empower individuals to act in accordance with the dictates of their own individual wills, provided their actions do not inhibit the equal ability of others to do likewise.
Libertarian philosophy further recognizes that the initiatiation of physical force, the threat of physical force, or fraud, are the only means by which individuals might be prevented from acting in accordance with the dictates of their own wills.
Hence, in order to recognize the moral legitimacy of rights, libertarian philosophy must prohibit the initiation of physical force, the threat of physical force, or fraud.
Having laid these foundational stones, we can now move on to interpretation and application of the philosophy. This is typically where most of the confusion comes in.
The most common misunderstanding of Libertarian philosophy, regards the prohibition against initiated force. Some mistakenly believe that such a prohibition would leave individuals or state powerless to act in defense of rights. But such is not the case. The prohibition, is against initiated force, and not force in general. So if an individual is the victim of force initiated by another, he may morally employ force in his own defense, and/or state may morally move to employ force to restrain and punish the violator.
Libertarian philosophy prohibits these things, because it recognizes the notion of rights. Rights empower individuals to act in accordance with the dictates of their own individual wills, provided their actions do not inhibit the equal ability of others to do likewise.
pro·hib·it
1 : to forbid by authority : ENJOIN
2 a : to prevent from doing something b : PRECLUDE
synonym see FORBID
How does libertarian philosophy -- or any philosophy -- prohibit anything? To prohibit one needs laws or rules and some means of enforcement. And is it that "rights empower individuals, etc." or simply that one has no rules forbidding or restraining them? Individuals act as they see fit and face punishment if they have violated the laws.
"Inhibit" is another tricky word. As is "rights." Lawyers know just how elastic the idea of "rights" -- especially "equal rights" --can be. Some things that libertarians question, like environmental and anti-trust laws, fit or can be made to fit under your principle. And libertarians have had real trouble dealing with such wholly state-created "rights" as trademarks, copyrights, and patents. For are these rights, or the inhibition of the rights of others?
In general, there are so many different forms of force and fraud, so many different ways of inhibiting, prohibiting, or infringing the equal rights or action of others that one can build up a fairly sized state within the limits of such libertarian principles. And if one is successful at building up such a state, it won't long remain within the bounds of libertarian principles, for having built up a competent state machinery, it will inevitably seek to expand its powers under the pretext of applying the same competence to other areas of life. The strength of libertarianism now results from the failure of the state in those areas, but it was precisely the success of the "minimal state" that tempted people to expand government powers.
Very many people would probably accept "libertarian principles," but load them down with so many caveats and exceptions that the result would not be so very different from what we have today. And that seems to be how things developed historically. What you want to use to cut back the state was, given a few different interpretations, used to build it up.