terminology help

[greekbum]

Are there any guidelines to use when describing a watch to somebody ?
This week I had a fellow collector show me a watch that he recently bought. He believes he bought a NOS 40 plus year old watch. It was in great condition but not NOS by any definition I know. He asked me my opinion and when I pointed out to him my observations of the case polishing, service marks inside the case back, etc he got offended and told me its NOS. I was at a loss for words….. I thought to myself with all this confusion in terminology recently are there clear definitions or guidelines that we have or should follow when using certain words as collectors,dealers or enthusiasts ? Below are some of the words I see often describing a watch or a part. I may have left a few out but does anybody care to define them ?
Mint (means like new and flawless)
Unpolished (NEVER Polished since it was manufactured)
NOS (A Watch or Part that was manufactured long ago but that has never been used or sold retail.)
Rare (Something hardly ever seen)
Tropical (A dial that has turned brown for various reasons) not water etc.
Original (Original to the watch when it was manufactured or original Rolex part)
Serviced (A Rolex service, independent etc needs to be clear)