Final answer:
The exact day a specific fraternity took a more definite form is not given, but the question refers to the history of fraternities and sororities, including milestones such as the founding of Alpha Kappa Alpha at Howard University in 1908.
Step-by-step explanation:
The question about the day on which a fraternity took a more definite form does not pertain to a specific event but is likely related to the broader history of fraternities and sororities in general. Notably, the mention of the National Pan-Hellenic Council in the reference material points to the formation of the historically African American fraternities and sororities. In 1908, Howard University established several fraternities, including Alpha Kappa Alpha, the first Black women's intercollegiate Greek organization founded at a Black university. This organization is recognized for its influential members such as Kamala Harris and Toni Morrison, and such events in fraternity history mark significant steps towards formal organization and incorporation.