1.
front line; forefront; top level
The leading position in a field, profession, or activity. Often used to describe someone who is active at the highest level.
第一線で活躍する。
To be active on the front line.
彼女は長年業界の一線で活躍してきた。
She has been active at the forefront of the industry for many years.
引退して一線を退いた後も、後進の育成に力を注いでいる。
Even after retiring from the front line, he devotes his energy to training the next generation.
2.
line; boundary; dividing line
A line that separates or divides, especially a moral or social boundary that should not be crossed.
一線を越えてはいけない。
You must not cross the line.
友情と恋愛の一線は難しい。
The line between friendship and romance is a difficult one.
冗談と侮辱の間には一線を画すべきだ。
One should draw a clear line between jokes and insults.
Composed of 一 (one) + 線 (line). Has two primary uses: referring to the leading edge of a field, and to a boundary or dividing line.
COMMON COLLOCATIONS:
- 一線で活躍する: to be active at the forefront
- 一線を退く: to retire from the front line
- 一線を越える: to cross the line
- 一線を画す: to draw a line (between); to distinguish clearly
- 第一線: the front line; the forefront
USAGE:
The expression 一線を画す is particularly common and means to make a clear distinction or to set oneself apart from others. 一線を越える often has moral or social implications — crossing a boundary that shouldn't be crossed.
SIMILAR WORDS:
- 最前線: the very front line — more emphatic than 一線
- 境界線: boundary line — more concrete and geographical than the figurative 一線