Ranger is a noun a name of an occupation. Rangers are people who look after large national parks or forests they sort of act like police but may not have the powers of police and in the US military some soldiers are called rangers. Also the Texas Rangers are a famous police force going back to the days of cowboys. The name comes from the verb to range, the area one can go, the distance or area a ranger has responsibility for. Or the area cattle can move about in, on the range. Range can also mean the grouping of common things like the range of her singing voice. Or the range from high to low of the prices of things. I don't know any other use of ranger that doesn't come from the verb to range.

Without knowing the context, I can only give you a dictionary definition. http://learnersdictionary.com/definition/ranger

Hi, since it is a bit elementary to find the meaning of some words on the web, is there any context in which this word might have appeared to you "ambiguous" -- so that we might puzzle for the phrase to be talking about 1. a kind of car, rather than 2. a specialized soldier 3. a law officer -- or how many other meanings does this word have, making me confused about it?