I doubt if my one year of chemistry at uni qualifies me as a chemistry nerd - certainly I can't remember if I ever titred anything. In fact I had to look it up to find its meaning.
Titration, it seems, is a procedure for measuring the concentration of some substance in a solution by gradually adding some other substance until it produces an observable result. Feel free to correct me if I've got that wrong, ridethetalk. The concentration so determined is called the titre.
Most dictionaries don't list titred, or give titre as a verb. The commonly used verb for this process is titrate. However, Wiktionary does have titre as a verb. And Merriam-Webster lists the US version, titered as an adjective derived from the noun titer. Titered is currently not accepted in Chi either.
In practice titred appears often in phrases like high titred and low titred. The same applies to the American spelling.
I'll add titred and titered as rare words.
