navathy
Nonagenary.
A 90th birthday anniversary is commonly referred to as a "90th birthday" or a "90th birthday celebration." Some people may also call it a "ninetieth birthday" or a "90th birthday milestone."
Platinum year
The traditional color scheme for a 60th anniversary is diamond white, with diamonds being the traditional gemstone to symbolize this milestone. However, modern interpretations may also include silver and royal blue as complementary colors for a 60th anniversary celebration. Ultimately, the choice of colors can be tailored to suit individual preferences and themes for the occasion.
A 75th birthday anniversary is commonly referred to as a "diamond jubilee."
A quincentennial is 500 years. It signifies a significant milestone, usually associated with commemorating an event or anniversary that occurred 500 years ago.
90th = ninetieth
One-ninetieth
Sesquicentennial
One
Down in the Depths - On the Ninetieth Floor - was created in 1936.
Centaped
* If you are announcing on an invitation 'Wedding Anniversary' then yes, that could be one way of doing it, but not necessary. If you are writing the word 'Wedding Anniversary then on the first letter in each word is capitalized.
Ninetieth.
That would be ninetieth.
Two hundred year anniversary, but that's not "one word".
No, there is only one for a full one hundred year-period, the 'centennial'.
Yes, the word 'birthday' is a noun, a word for the day or the anniversary of a person's birth; a word for anniversary of something beginning; a word for a thing.