What is the correct past-participle inflection of the verb ‘weightlifting’ – and why?

Question

What is the correct past-participle inflection of the verb weightlifting, and why?

1. Weightlifted.
2. Weight-lifted.
3. Both (1) and (2) are valid and mean the same thing.
4. Either of (1) or (2), but which to use varies by context.
   ^{If this case applies, please explain the contexts requiring form (1) versus those requiring form (2).}
5. Neither (1) nor (2) but rather some other term than these two.
   ^{If this case applies, please provide that other term.}
6. Neither, and there cannot ever be one.
   ^{If this case applies, please explain why there cannot be one in the first place.}

Answer 1

Weightlifting is most often a noun, and nouns don't have past participles. The corresponding verb is usually expressed not by a single word, but by the phrase "to lift weights". I haven't found any entries in a traditional dictionary for a verb weightlift, although you can see it, marked "rare", in Wiktionary.

The incorporation of an object into a word is most commonly seen in nouns or adjectives derived from verbs, not so often in verbs themselves, as I mentioned previously in relation to the adjectives spellbound and spellbinding and the noun blameshifting.

There is no editorial guideline that says to use a hyphen only in some parts of a verb, but not in other parts of the same verb. If you for some reason decide to use "to weightlift" as a verb, its past participle would be weightlifted and its gerund/present participle would be weightlifting. If you use "to weight-lift" as a verb, its past participle would be weight-lifted and its gerund/present participle would be weight-lifting.

There aren't general rules about whether compound verbs like this, or compound words in general, should be spelled with or without a hyphen. But the general trend in recent centuries has been towards less use of hyphens than in the past: "weight-lifting" itself used to be a commonly used spelling, but has now been overtaken by weightlifting. I'd therefore advising using the non-hyphenated spelling if you make use of a verb weightlift, weightlifted, etc.

Answer 2

Despite the existence of the verb-derived gerund weightlifting, the "base form" to weightlift doesn't exist (it's not in the full Oxford English Dictionary, Collins, or Merriam-Webster, for example).

So it's a bit pointless asking how to "correctly" write the past participle of the "non-verb". The associated verb phrase (not "phrasal verb") is to lift weights, with past tense He lifted weights.

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But if you don't mind using terms that are not (yet?) endorsed by traditional dictionaries, the logical choice must be unhyphenated. Many two-word collocations have undergone an intermediate hyphenated phase before becoming established as single words, which makes the hyphenated forms look old-fashioned today.

Unquestionably to weightlift is a fast-rising neologism. So skip the "dated" orthographical phase.

Answer 3

Weightlift, and weight-lift are both in use as verbs informally, and seeing as how they're rather rare and there don't appear to be any authoritative dictionary entries, both forms are on the table as a base for the past participle.

There's at least one convincing published use for weight-lifted as the past participle.

Betty, whose son had weight-lifted with Tom and Dan when the two of them were doing it twice a day and drinking carrot juice and other concoctions that were ...(New England Review, Robert Oldshue)

Weightlifted as past participle appears in a few places online.

Mr Williams, 45, who has weightlifted for Wales nine times, has completed more than 22 sponsored truck and doubledecker bus pulls, two London Marathons and has even bared all for a charity calendar, but admits boxing is all new to him. (South Wales Argus)

Magni, a science teacher at Pioneer Valley High School, has weightlifted for 21 years. (Santa Maria Sun)