In a recent submission, one of the writers used the word “dethaw” in a story. A couple of us questioned this word. I, for one, have never heard it or seen it in print.
Web research shows that it may be a word. The meaning of dethaw is that something becomes or is caused to become soft or liquid.
The website Yahoo Answers had a long explanation of the term dethaw some years ago. In part, here is what johndiva said in his answer on the website.
THAW and DEFROST are cognates — the first one comes from Germanic and the second word from Latin. Therefore, you can use them interchangeably as synonyms.
We inherited the prefix “de-” from Latin. It literally means “down from,” “off,” or “concerning.” Thus, DEFROST originally meant to “frost down” or “frost off.” Since THAW already means, “to melt,” we wouldn’t add a prefix which implies downward motion because English-speakers assume that the melted water will drain in that direction.
We typically reserve Latin affixes for words which derive from Latin (although we do have numerous exceptions to this rule!). Because THAW came from Germanic, it sounds more standard to native speakers if you use a Germanic affix (that’s why so many people find “dethaw” strange).
In this case, most people would prefer or say “unthaw” because “un-” usually expresses the same sentiment as or “dis-” or “im/in-” in Latinate words … all these prefixes mean “not” [or “opposite”].
However . . . “dethaw” isn’t entirely incorrect. I found an entry online at “dictionary.com” for this word. I suspect it’s a more recent trend, and something brought about by the fact that DEFROST & THAW are similar ideas: people take a prefix they know means “downward process” & add it to THAW to emphesis that someone/something causes the melting action.
“Dethaw the meat” = “to take the meat out of the freezer and let it thaw.” i.e. “She will dethaw her supper when she gets home from work.” In this context “de-” seems to carry on a new meaning and not “down” or “off.”
Personally, I’ve never heard DETHAW used in a sentence, but that doesn’t mean anglophones don’t use it. I don’t think it would mean “to counter the thaw” or “to freeze again.” That would be REFREEZE [it was already frozen once before you had to thaw it, so the second time takes the prefix “re-”
So according to this info, dethaw is a word. A counterpoint is made by Wiktionary.com where the state that this term generally is regarded as nonstandard and an illiterate term for thaw; consequently, it is usually inappropriate in formal contexts.