The spelling of the word "RDMATH" can be phonetically transcribed as /ɑːrdˈiːmæθ/. The word is a combination of the abbreviated form of "arduous" (/ɑːrˈdjuːəs/) and "mathematics" (/mæθəˈmætɪks/). It is a term used in academic and research settings to describe a difficult or complicated mathematical problem or concept. The unusual spelling of "RDMATH" is likely a result of merging the two words and omitting some of the letters for brevity.