As a point of order: Optionitis is the correct word in its singular use. Optionitus is the plural . The exact opposite of the usage of Hippopotamus and Hippopotami. Please note for the future. Many thanks and have an outstanding day…
Hence my correct spelling and use above as its been all week so far, but thanks for providing guidance for others Pedant
So the answer is a 6 letter British word in a 5 letter puzzle I don't think I've ever heard or used this word, maybe just a lack of enthusiasm or intense love for the matter. A lucky 3 for me as I couldn't make anything else fit the gaps.