Merriam-Webster Collegiate Edition, HK's dictionary of choice, is an excellent resource. But it's wrong about some things. The two most notable errors in M-W are sport terminology and hyphenation of adverbs.
It appears that the editors of M-W haven't consulted national governing bodies of sports when determining the
correct styles of various sport terms. Here are examples of terms that appear in M-W (and these are all incorrect):
at bat (n)
dead lift (n)
lutz, salchow, and other eponymous sport moves (lowercase)
tae kwon do (n)
weight lifting, weight lifter (n)
wet suit (n)
But those styles aren't the industry standards in their respective sports, and some of those styles aren't logical. Here are the correct styles:
at-bat (n): This should be hyphenated as noun and adjective. If it's left open as a noun or adjective, it's ambiguous.
deadlift, deadlifting (n, adj): This is one word (industry standard).
gymnastics (adj): Gymnastic isn't a word. All competition names and club names use gymnastics as the adjective form: world gymnastics championships, national gymnastics championships, Chow's Gymnastics Club. The correct styles are gymnastics mat, gymnastics move, gymnastics competition.
Lutz, Salchow, and other eponymous sport moves: Capitalize these because the moves are named after the people who invented the skills.
taekwondo (n): This is one word (industry standard).
tee ball: The ball is hit from a tee, so it's tee ball.
weightlifting, weightlifter (n): This is one word (industry standard).
wetsuit (n): This is one word (industry standard).
M-W tends to hyphenate compound adverbs and predicate adjectives that are commonly occurring phrases. But that doesn't make sense because many other not-so-common compound adverbs are parallel in structure (i.e., they contain the same elements) but they don't contain hyphens. Consider these adverbs and predicate adjectives that M-W indicates should be hyphenated:
out-of-bounds (adv): Erroneous examples are "The gymnast stepped out-of-bounds" and "The gymnast was out-of-bounds."
up-to-date: Erroneous examples are "I'm up-to-date on my immunizations" (predicate adj) and "She brought her certification up-to-date" (adv).
off-limits: An erroneous example is "Greesy cheeseburgers are off-limits" (predicate adj).
one-on-one: An erroneous example is they met one-on-one for several hours (predicate adv)
As noted, all those examples of hyphenations are wrong. M-W doesn't dictate hyphens for out of date
as a predicate adjective. So why would be need to hyphenate an expression that's similar to that? I say we