I would have fought him to the teeth for her

A physical therapist was talking about a new hire that another PT wanted to also hire. The new hire was apparently great. This is a mashup of “fight tooth and nail” (engage in vigorous combat) and “fight to the death” (intensely pursue an outcome refusing to accept defeat). Both expressions have the word “fight” which is the source of the mental mixup. “Tooth and nail” seems to be an idiom frequently messed up, considering I have posted others – see https://malaphors.com/2021/02/15/we-fought-each-other-like-tooth-and-tongue/ and https://malaphors.com/2018/06/29/they-are-scrambling-tooth-and-nail/. Also, if you type “teeth” in the search engine, there are many malaphors associated with our little chiclets. Props to Barry Eigen for hearing this one and sending it in.