How about, Right is when people understand you and Wrong is when they don't?
Good working definition, so long as it is sustainable.
When I worked in lighting, there was a difference between a lamp, a lantern, a light and a lunimaire, not to mention the differences between floods, spots, fresnels, pars (38, 56 or 64) and specific model numbers.
When i was teaching students, they often used 'lamp' for 'lantern', and wondered why I kept getting on their case about it. If they asked another trainee for a lamp, they usually got handed a lantern, which was OK. But there are times when it makes an awful lot of difference. Like the time one lad was asked to bring a lamp up to the grid. He walked up five flights of stairs with a Par 64 lamp, only to find out that what the person requesting had wanted was another
lantern. Words were had, and both understood the reason for using words carefully.