こっそり（こっそり、koっsori）
- secretly

The Japanese word こっそり generally means "secretly," "stealthily," "furtively," or "on the sly." It describes an action done quietly, without being noticed, or in a way that is hidden from others. It implies a degree of secrecy, often with a hint of mischievousness or carefulness to avoid detection. It can also describe the state of being hidden or the manner of doing something to not be detected. The core concept is about doing something privately, out of sight, and without attracting attention. The meaning extends to the idea of performing actions carefully, or surreptitiously.

⚫︎ こっそりお菓子を食べる。 Translation: I eat snacks secretly. ⚫︎ 誰も見ていないか、こっそり周りを見渡した。 Translation: I glanced around secretly to see if anyone was watching. ⚫︎ こっそりプレゼントを準備した。 Translation: I prepared the present secretly.

⚫︎ Use こっそり when you want to describe an action done in a hidden or private manner. ⚫︎ It is appropriate when you want to emphasize that the action is done without others knowing. ⚫︎ Often used to express actions done to avoid being seen or heard, such as eating food without permission, sneaking into a place, or giving a gift secretly. ⚫︎ The word is typically used with verbs that describe actions, such as "to eat," "to look," "to prepare," "to go," etc. The nuance is always to keep the action a secret.

⚫︎ こっそり is usually written in hiragana. ⚫︎ There is no standard kanji for こっそり. ⚫︎ The okurigana (the suffix hiragana) is always "り." ⚫︎ The word itself, こっそり, is the adverbial form. The base form is unknown and rarely used.

⚫︎ ひそかに (hisoka ni): Secretly, privately. This is a more formal synonym. ⚫︎ こっそりと (こっそり to): This is the adverbial form, a slightly more emphatic variation. ⚫︎ 内緒で (naisho de): In secret, privately. ⚫︎ こそこそと (kosokoso to): In a stealthy and hushed manner. This implies more furtiveness. ⚫︎ こまごまと (komagomato): Secretly, quietly.

⚫︎ おおっぴらに (ōppira ni): Openly, publicly. ⚫︎ 堂々と (dōdō to): With confidence, boldly. ⚫︎ 公然と (kōzen to): Openly, publicly.

先生に見つからないように、こっそりゲームをした。 ・Translation: I played the game secretly so the teacher wouldn't see me. ・Explanation: This sentence illustrates the action of playing a game, the manner being secret to avoid the teacher's notice.

友達にこっそり誕生日プレゼントを渡した。 ・Translation: I secretly gave my friend a birthday present. ・Explanation: The sentence highlights the act of giving a present, emphasizing that it was done secretly.

The exact etymology of こっそり is not entirely clear. It is thought to be an onomatopoeic word, similar to the sound one might make when moving quietly. It is related to the idea of stealth and secrecy, and the repetition of the sound "ko" might be for emphasis, although there is no definitive proof.