IPA: /eɪθ/
KK: /eɪtθ/
A part of something that is divided into eight equal parts, or the position of eight in a sequence.
She finished in eighth place in the race.
Eighth → The word is formed from "eight" (from Old English "eahta", meaning the number 8) and the suffix "-th" (used to form ordinal numbers). Thus, "eighth" refers to the position of being the eighth in a sequence.
Think of the number 'eight' and remember that 'eighth' means the position that comes after seven.