キャップ（キャップ、kyaッpu）
- cap

The Japanese word キャップ (kyappu) is primarily used to mean "cap" in English, referring to several different types of caps. It can refer to a hat, a bottle cap, or even a protective cover. It's a loanword from English. The specific meaning depends heavily on the context in which it's used.

⚫︎ 野球のキャップ Translation: Baseball cap ⚫︎ ボトルのキャップをあける Translation: To open the bottle cap ⚫︎ ペンにキャップをつける Translation: To put the cap on the pen

キャップ is a versatile word used in many situations: ⚫︎ When discussing headwear, especially casual hats like baseball caps or trucker hats. ⚫︎ When referring to bottle caps, the part you twist or pry off. ⚫︎ When talking about protective covers for things like pens or equipment. ⚫︎ The word is generally informal and commonly used in daily conversation. ⚫︎ The word is useful in many settings.

キャップ is written in katakana, キャップ. This is because it's a loanword from English. ⚫︎ There are no other standard ways to write this word. ⚫︎ The okurigana is not applicable.

⚫︎ 帽子 (boushi) - hat (general term) ⚫︎ 蓋 (futa) - lid, cap (for containers) ⚫︎ カバー (kabaa) - cover

There aren't direct antonyms, but you could consider the opposite action depending on the context: ⚫︎ For a bottle cap: taking off the cap (キャップをあける) ⚫︎ For a hat: taking off a hat (帽子を脱ぐ)

夏は、いつもキャップをかぶります。 ・Translation: In summer, I always wear a cap. ・Explanation: This sentence uses キャップ to refer to a hat worn during the summer.

このボトルのキャップは固くて開かない。 ・Translation: This bottle cap is hard and won't open. ・Explanation: This sentence uses キャップ to refer to the cap of a bottle.

The word キャップ (kyappu) comes directly from the English word "cap."