No, I did not suggest the definition and explanation as content for them to use. I was trying to explain a concept that they discussed incorrectly multiple times in the paper. It is an advanced concept that might not even appear in graduate-level courses on the subject, so I can understand why they did not understand it fully. That said, I did not give them permission to copy my words there. If there are any particular changes I want the authors to do I put them in quotes. This wasn't in quotes. It was an explanation for their own benefit so that they can correct the mistakes in the paper (by re-writing it).
Once I re-read the submission I wanted to reject it immediately, but I realized that I should get a second opinion first. So I contacted the editors, who agreed that it was blatant plagiarism. Hence, they rejected the paper once I recommended rejection in my second review. So this wasn't just a conversation where I made some suggestions and the authors used them. Even the editors thought it was plagiarism once they looked at it.
An acknowledgment would be impossible because the review was single-blind. The reviewers knew the identities of the authors but not the other way around. What the authors should have done was just re-phrase where they used the term in the paper. They didn't even need to copy my explanation, to be frank. The paper would worked fine without the paragraph they copied. If they just re-phrased the relevant parts no other changes would have been needed and this whole thing could have been avoided.
Once I re-read the submission I wanted to reject it immediately, but I realized that I should get a second opinion first. So I contacted the editors, who agreed that it was blatant plagiarism. Hence, they rejected the paper once I recommended rejection in my second review. So this wasn't just a conversation where I made some suggestions and the authors used them. Even the editors thought it was plagiarism once they looked at it.
An acknowledgment would be impossible because the review was single-blind. The reviewers knew the identities of the authors but not the other way around. What the authors should have done was just re-phrase where they used the term in the paper. They didn't even need to copy my explanation, to be frank. The paper would worked fine without the paragraph they copied. If they just re-phrased the relevant parts no other changes would have been needed and this whole thing could have been avoided.