What is the connection between the fact a vehicle has six wheels and the suffix "er" in "six-wheeler" and the suffix "er" in three-pointer?
Is it grammatically correct to use the "er" suffix like that, or is it just street language?
What is the connection between the fact a vehicle has six wheels and the suffix "er" in "six-wheeler" and the suffix "er" in three-pointer?
Is it grammatically correct to use the "er" suffix like that, or is it just street language?
The suffix -er is used in various constructions to form nouns that have some characteristic. You probably know the use of -er to form agent nouns "builder = a person that builds"
They are also used with number-unit expressions to form nouns characterised by that amount.
nine-footer = something that is nine feet long, (eg a boat)
first grader = someone in the first grade of school
"Six-wheeler" follows this use, as does "three-pointer". This is correct grammar.
But it might be fairly informal, as it assumes you understand what kind of thing you are talking about. If you say "What is she -- a 24-footer?" You could be talking about boats or snakes.
So "six-wheeler", like other short forms, tends to be more casual than a longer but clearer "six-wheel truck". Likewise "three-pointer" compared to "three-point shot".
And there is no guarantee that a particular example has much actual use. As mentioned in comments, "four-footer" would not an idiomatic way to refer to an animal with four feet.