Pronunciation: [ˈe͡ɪti fˈɜːst] (IPA) 
The spelling of "eighty first" is quite unique, as it is a compound word made up of two different numbers. The first part, "eighty," is spelled with the long "a" sound represented by the IPA symbol /eɪ/. The second part, "first," is spelled with the short "i" sound represented by the IPA symbol /fɜrst/. Together, these two words create the unique pronunciation of /ˈeɪti fɜrst/, which is the correct way to say "eighty first."
"Eighty first" refers to the ordinal number that follows number 80 in a series or sequence. It is derived from the cardinal number 81, which signifies a quantity or count of 81 individual items. In the context of ordinal numbers, "eighty first" represents the position or rank of the 81st item in a series, list, or order.
The term "eighty first" is constructed by combining the cardinal number "eighty" with the ordinal suffix "-th." The number 80 is derived from the base numeral system, where it is composed of eight tens, and it is followed by the simple suffix "-ty" to create "eighty." The ordinal suffix "-th" is then added to denote the position of the number in the sequence.
For example, if there is a line of 100 people, "eighty first" refers to the person who is positioned at the 81st spot when counting from the beginning of the line. Similarly, in a list of 100 items, "eighty first" indicates the item that occupies the 81st place if the counting starts from the top. The term "eighty first" can be used to describe various concepts and objects that hold the 81st rank within a specific context, such as the 81st chapter of a book, the 81st day of the year, or the 81st floor of a building.
The word "eighty first" is a combination of two words: "eighty" and "first".
The term "eighty" originated from the Old English word "eahtatig", which is a combination of "eahta" (eight) and "-tig" (suffix referring to ten). This Old English word evolved into "eighty" in Middle English.
The word "first" came from the Old English word "fyresta", which means "foremost" or "earliest". It has roots in the Proto-Germanic word "*furisto".
When "eighty" and "first" are combined, they form the compound word "eighty first", which refers to the ordinal number representing the numerical position immediately after eighty.
