亀裂|きれつkiretsu[0]heiban (flat)

1. nouncrack; crevice; fissure; chap; rift
   耐震性たいしんせいの悪わるい建物たてものに亀裂きれつが生しょうじることもある。↗

   Also cracks may form in buildings that aren't Earthquake proof.

• SynonymクラックNeutralLoanword used in technical fields like construction and materials; also means hacking into computer systems. 「亀裂」 is more general, also used for rifts in relationships.
• SynonymひびWrittenUsually written in kana as 「ひび」; the kanji 「罅」 is rare. Fine cracks on vessels and walls, or a rift between people. 「亀裂」 is a Sino-Japanese word used in written prose.
• Synonym裂け目さけめNeutralA linear tear or split, as in 「地面の裂け目」. 「亀裂」 focuses on the crack itself and can also describe a rift in a relationship.
• Synonym割れ目われめNeutralA gap formed when something breaks apart; common in everyday speech. 「亀裂」 is more written, used mainly for walls and strata, and also describes rifts in relationships.
• Related割り目わりめNeutralA gap left after something splits or is cut, as in 「岩の割り目」. 「亀裂」 emphasizes surface cracks spreading like a tortoise shell.
• Relatedひび割れひびわれNeutralCracks on surfaces such as walls, glass and skin; can also be a verb. Common in daily use; 「亀裂」 is more written and can also describe a rift in a relationship.

For cracks in the ground or walls and for rifts in relationships, written prose favors 「亀裂」, as in 「関係に亀裂が入る」. Everyday fine cracks are 「ひび」 or 「ひび割れ」; gaps from splitting or tearing are 「割れ目」 or 「裂け目」.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 亀かめの甲羅こうらのように走はしる裂さけめや割れ目われめのこと。