額（ひたい、hitai）
- forehead

The Japanese word 額 額 (hiragana: ひたい) primarily means "forehead." It refers to the part of the face above the eyebrows and below the hairline. It can also figuratively refer to something that looks like the forehead.

⚫︎彼の額には汗が光っていた。 Translation: Sweat glistened on his forehead. ⚫︎彼女は額に手を当てて考え込んだ。 Translation: She put her hand to her forehead and pondered. ⚫︎その絵の額縁が美しかった。 Translation: The frame of that painting was beautiful. (Here, 額 refers to the frame, which can be seen as "forehead-like" around the picture.)

This word is commonly used in everyday conversations to describe the physical feature of a person's forehead. It's also used in more abstract ways, such as referring to the front of a structure or the frame of a picture. When used to refer to a frame, it is usually written in kanji.

⚫︎The standard way to write this word is 額 (kanji) and ひたい (hiragana). ⚫︎The okurigana (hiragana following the kanji) is not applicable because 額 itself is the head noun.

There aren't many direct synonyms for "forehead" in Japanese, but words that could be used in related contexts include: ⚫︎前頭部 (ぜんとうぶ) - forehead (medical or technical term) ⚫︎顔 (かお) - face (can be used to refer to the general area including the forehead, but not specifically the forehead itself)

There aren't direct antonyms for the forehead itself. The concept has no direct opposites.

彼女は額に絆創膏を貼っていた。 ・Translation: She had a Band-Aid on her forehead. ・Explanation: This sentence describes a common scenario where the word 額 is used to specify the location of the Band-Aid.

試験の結果を見て、彼は額に冷や汗をかいた。 ・Translation: Looking at the test results, he broke out in a cold sweat on his forehead. ・Explanation: This sentence describes someone's feeling of fear or anxiety and illustrates the use of 額 with the expression "冷や汗をかく" (to break out in a cold sweat).

The etymology of 額 isn't definitively known. However, its usage as a noun referring to the part of the face above the eyes has been used for centuries, with its origins in classical Japanese.