fourth
Longman Dictionary of Contemporary English 5++LDOCE 5++fourth1 /fɔːθ $ fɔːrθ/ ●●● S3 W3 adjective coming after three other things in a series 第四（个）的 in the fourth century 在四世纪 her fourth birthday 她的四岁生日 —fourthly adverb
Examples from the Corpus
fourth• Her apartment was on the fourth floor.• Mark is starting fourth grade in the fall.fourth2 ●●● S3 W3 pronoun the fourth thing in a series 第四个 the fourth of July 7月4日fourth3 noun [countable] HMN¼; one of four equal parts 四分之一one-fourth/three-fourths 四分之一/四分之三 → quarter1(1)From Longman Business Dictionaryfourthfourth /fɔːθfɔːrθ/ adjectiveACCOUNTING fourth half/quarter/period the fourth half, quarter etc of the financial yearOrigin fourth1 Old English feortha, from feower “four” Business a three coming other after Corpus in series things
fourth
fourth1 /fɔːθ $ fɔːrθ/ 
adjective
in the fourth century
her fourth birthday
—fourthly adverb
fourth2 pronoun
the fourth thing in a series:
the fourth of July
fourth3 noun [countable]
¼; one of four equal parts
one-fourth/three-fourths ⇨ quarter1(1)
| I |
adjective Language: Old English
Origin: feortha, from feower __four__
coming after three other things in a series:Origin: feortha, from feower __four__
—fourthly adverb
| II |
pronounthe fourth thing in a series:
| III |
noun [countable]¼; one of four equal parts
one-fourth/three-fourths ⇨ quarter1(1)