貝（かい、kai）
- shellfish

The Japanese word 貝 (かい) primarily means "shellfish" or "shell." It refers to any marine or freshwater animal with a shell, such as clams, oysters, scallops, and mussels. The word encompasses both the animal itself and the shell it creates.

⚫︎ 貝殻 (かいがら) Translation: Shell (specifically, the empty shell of a shellfish) ⚫︎ アワビの貝 (あわびのかい) Translation: Abalone shell ⚫︎ 貝を食べる (かいをたべる) Translation: To eat shellfish

You use 貝 in situations where you are talking about shellfish, shells, or things related to them. This can include: ⚫︎ Describing what you ate (e.g., shellfish for dinner). ⚫︎ Talking about the beach and finding shells. ⚫︎ Referring to the type of animal with a shell.

⚫︎ Kanji: 貝 ⚫︎ Hiragana: かい ⚫︎ Katakana: This word is not typically written in katakana unless used for emphasis or to represent a foreign word (e.g., "shell" in English). ⚫︎ There are no variations in okurigana (the suffix hiragana).

There aren't many direct synonyms for 貝, as it is a specific term. However, words related to shells and shellfish could be considered related: ⚫︎ 貝殻 (かいがら) - shell ⚫︎ 二枚貝 (にまいがい) - bivalve ⚫︎ 巻き貝 (まきがい) - snail shell

There are no direct antonyms for 貝.

海で[貝]を拾いました。 ・Translation: I picked up a shell at the beach. ・Explanation: This sentence describes finding a shell, using the word [貝] to refer to the object found.

今日の夕食は[貝]づくしです。 ・Translation: Dinner today is all about shellfish. ・Explanation: This sentence uses [貝] to indicate that the meal consists of various shellfish dishes.

The etymology of 貝 is not definitively known, but it is believed to be an ancient Japanese word that has always been used to refer to shellfish.