I would guess this arose with "wet" as a depictive modifier of the verb. But synchronically it doesn't feel like that—"He was soaking wet" is just a copular sentence, with "soaking" intensifying "wet", and does not license the question "When was he soaking?".
The actual EWT sentence says "[it] must be soaking or damp wet". "Damp" would normally be an ADJ so this is kind of an odd construction. I wonder if in the mind of the writer "soaking" is an ADJ that exceptionally modifies another ADJ, and can therefore be coordinated with "damp".
amod(ADJ, ADJ) is well-attested for compounds ("open ended") and also occurs in GUM for color subcategories ("inky black", "pale brown"). So maybe that's the best solution here.
MW calls this an idiom:
I would guess this arose with "wet" as a depictive modifier of the verb. But synchronically it doesn't feel like that—"He was soaking wet" is just a copular sentence, with "soaking" intensifying "wet", and does not license the question "When was he soaking?".
The actual EWT sentence says "[it] must be soaking or damp wet". "Damp" would normally be an ADJ so this is kind of an odd construction. I wonder if in the mind of the writer "soaking" is an ADJ that exceptionally modifies another ADJ, and can therefore be coordinated with "damp".
amod(ADJ, ADJ) is well-attested for compounds ("open ended") and also occurs in GUM for color subcategories ("inky black", "pale brown"). So maybe that's the best solution here.