Some words are used interchangeably. This certainly enriches a languages by giving it alternative ways of expressing the same idea — or so it is believed! Not so. An idea, object, or event (three different non-alternative entities!) may go under different names, as when a married woman refers to herself both by her maiden and her husband’s name, or when a person is described as married or wedded, or a diamond is described as a stone or gem, or an engine-propelled boat is referred to as a steamer or liner.
In some cases the names were wrought at different times and their names reflect this. A steamer clearly is a boat whose engines are driven by a mechanism whose pistons are moved by steam which is produced by burning coal or oil, whereas a liner is a bigger boat whose propellers or pressure operated valves may be moved by turbines and which carries passengers across oceans, not on rivers and lakes.
Language can be so rich — grammar arid.
A definition is a device used rigidly or loosely, which is to it intended to “fix” a word, to assign it meaning. Rigid definitions are preferred in scientific disciplines where ambiguity is deliberately shunned. Accordingly, a word cannot (should not!) have two or more uses. Each label on the bottle must be completely unambiguous, have only one interpretation and fully describe or identify the content of the bottle. Most dictionary definitions, by contrast, are nonrigid, sometimes even fuzzy. What such definitions accomplish is to draw a circle around a claim. Inside and outside the circle are entirely and insufferably different. These demarcate — inform us — what a word means — but also what it does not mean! (Most of us live in a bi-modal world most — but not all — of the time!)
A clarification as a device tells us, in words we are expected to understand, what an unknown or ambiguous word or expression could mean and what it probably means in the context provided. A clarification may ease us into understanding a sentence in which the problematic word occurred! It does not scream at us “You used the word or expression incorrectly, falsely, heinously!” but indicates that we trespassed on an existing good usage of a word. It says: “No! it is no a liner, but a paddle steamer”. It has explained, has clarified that the word used was not the best word to use under the prevailing circumstance, and hereby opened alternative choices to us.