Incorrect Spelling: Tution

Explanation:
- The correct spelling of the word is "Tuition," not "Tution."
- The incorrect spelling of the word is a result of a typographical error, where the letter "i" is missing between "t" and "o."
- The correct pronunciation of the word is "too-ish-un," while the incorrect spelling would result in pronouncing it as "too-tion."
- The incorrect spelling, "Tution," does not align with the standard English spelling conventions.

Correct Spelling and Definitions:
1. Passion: A strong and uncontrollable emotion or intense enthusiasm towards something or someone. For example, "She has a passion for music."
2. Fashion: A popular or prevailing style of clothing, accessories, or behavior. For example, "She follows the latest fashion trends."
3. Ration: A fixed amount of a commodity that is officially allowed to each person during a time of shortage or scarcity. For example, "During the war, people had to survive on limited ration."
4. Tuition: Teaching or instruction, especially the work done by a teacher to help a student learn a particular subject or skill. For example, "He attends private tuition to improve his math skills."

Therefore, the word that is spelled incorrectly is "Tution," which should be spelled as "Tuition."