1.
parallel lines
Lines that run in the same direction and never intersect. A geometry term.
二つの線は平行線だ。
The two lines are parallel.
平行線は交わらない。
Parallel lines do not intersect.
平行線の性質を利用して作図する。
I'll use the properties of parallel lines to draw the figure.
2.
deadlock; impasse; no progress
A situation where two sides cannot reach agreement, like parallel lines that never meet. Used figuratively for negotiations or discussions that go nowhere.
議論は平行線のままだ。
The discussion remains at a deadlock.
交渉は平行線をたどった。
The negotiations reached an impasse.
双方の主張は平行線で、合意には至らなかった。
Both sides' positions remained at an impasse, and no agreement was reached.
USAGE:
Sense 1 is the mathematical term. Sense 2 is a very common figurative usage in news and everyday speech, describing negotiations, discussions, or opinions that cannot converge — like parallel lines that never meet.
COMMON COLLOCATIONS:
- 平行線をたどる (to reach an impasse)
- 平行線のまま (remaining at a deadlock)
- 議論が平行線 (the discussion is deadlocked)
SIMILAR WORDS:
- 膠着状態: stalemate — more formal, emphasizes being stuck
- 堂々巡り: going around in circles — repetitive lack of progress