unknown

不明の、未知の

誰にも知られていない、または理解されていない。

やさしい英語で： Not known or understood by anyone.

• The cause is unknown.
• Her exact date of birth remains unknown.
• They found a substance of unknown origin.

類義語： undetermined, unexplained

反対語： known

よく使う表現： unknown cause, remain unknown, unknown origin

無名の、身元不明の

誰なのか分からない、またはあまり知られていない。

やさしい英語で： Not recognized, named, or familiar to many people.

• An unknown caller left a message.
• The painting was by an unknown artist.
• She was relatively unknown before her first film.

使い方： unknown to someone (The young writer was unknown to most readers.)

類義語： unidentified, unfamiliar, obscure

反対語： famous, well-known

よく使う表現： unknown artist, unknown caller, relatively unknown

未知数

数学の問題で文字で表され、値を求める必要がある数。

やさしい英語で： A number represented by a letter in a maths problem whose value you must find.

• Find the unknown in this equation.
• The letter x represents an unknown.
• We solved two equations with two unknowns.

類義語： unknown variable

よく使う表現： solve an unknown, one unknown, two unknowns