also: しちぶだけ
noun which may take the genitive case particle 'no'
three-quarter length
Typically used for clothing that reaches about three-quarters of the full length, such as pants or sleeves.
夏は七分丈のパンツが涼しくて好きだ。
In summer, I like three-quarter length pants because they are cool.
この七分丈のカーディガンは春にちょうどいい。
This three-quarter length cardigan is just right for spring.
七分 (seven-tenths) + 丈 (length). The term describes a length that is about 70% of the full length.