KanjiJLPT N1
Reef

reef, sunken rock

Mnemonic

A massive stone jutting from the ocean floor has been charred black by ancient volcanic heat — this is the deadly reef that wrecks ships. Sailors fear its dark, scorched surface lurking just beneath the waves.
Additional thoughts
Visualize a blackened, scorched stone rising from shallow turquoise water — charred by undersea volcanic fire, it has hardened into a treacherous reef. Stone + Char = Reef.
Quick recall
A stone charred by volcanic fire forms a deadly reef.

Details

The keyword for 礁 is reef. This kanji refers to a rocky formation found in shallow waters, typically near coastlines or just beneath the ocean's surface. These submerged or partially exposed rock formations pose hazards to navigation and are often associated with coral growth in tropical seas. The character conveys the idea of hard, stony structures rising from the seabed in relatively shallow areas.
On'yomi
しょう