LOL. So if you learned that "conscious" means "relating to convicts" then that is a "correct" definition? No, you must put aside metaphorical usages of the word when trying to discuss it scientifically.
But you cannot ignore the way we use the word. A scientific use of the word must either be defined specifically and independently of common use (e.g., "positive punishment" in behaviorism, completely separate from what that phrase might mean to you and Mrs. Tricky), or--if it purports to examine the phrase we actually use in our language--it must define it
as it is used. You can define something away, if you try to; all you have achieved is answering a question that was never asked.
Depends on how skilled you are. If the definition of a thing must include all the characteristics of a thing, then you will kill a lot of frogs trying to define one, and you still will never have all its characteristics. At some point, you have to say, "this is enough to identify it", and even then be aware that you may have to correct yourself later.
An ethologist would suggest that you could also study frogs as they live in their environment. It answers different questions than dissection does, but then, dissection cannot be expected to give answers to those questions. The living frog, and the living language, must be studied as they actually interact with their environment. Put your scalpel away, Trixie.
But only an idiot would define "flying" that way, or else, I was "flying" my wife while she was tied up last night.
You may well have been; I wasn't there.

You and I both know that feathers were intended to be a necessary, but not sufficient, part of that definition. But...my best to Mrs. Trixie anyway. With feathers, even.
Of course not. In fact, by this definition, viruses are not alive. But it is reasonably complete, given that we don't have any examples of non-terrestrial life to help us refine the definition.
By other definitions, viruses are alive; by yet others, some entities which exist only within computer programs are alive. By still others, a language is alive.
Lines can be drawn, but they can also be redrawn.
Every snowflake is unique, but we do not confuse snowflakes with feathers. The definitions we use work well as we use them. It is when we stretch them, or ask them to do things they have never done before ("the moment", anyone?) that they balk, and refuse to obey us...gee, it is as if they have minds of their own...