トントン
とんとん
noun, adverb, onomatopoeia
knock-knock; break even
1.
knock-knock, tap-tap
The sound of light, rhythmic knocking or tapping, as on a door or with a knife while chopping.
ドアをトントンと叩く。
To knock on the door.
包丁でトントンと野菜を切る音が聞こえた。
I could hear the tap-tap-tap of vegetables being chopped with a knife.
肩をトントンと叩かれて振り向いた。
Someone tapped me on the shoulder and I turned around.
2.
break even, even
A state where gains and losses balance out, resulting in neither profit nor loss.
今月はトントンだった。
This month we broke even.
売上と経費がトントンで利益はほぼゼロだ。
Sales and expenses are about even, so profit is nearly zero.
副業を始めたけど、初期投資を考えるとまだトントンくらいだ。
I started a side business, but factoring in the initial investment, I'm still just about breaking even.
TWO DISTINCT USES:
The onomatopoeic sense (knocking/tapping) and the financial sense (break even) are unrelated in origin. The break-even meaning may come from the image of two sides being evenly balanced.
GRAMMAR:
As onomatopoeia: used with と: トントンと叩く (to tap/knock).
As break-even: used as a noun/na-adjective: トントンだ (to be break-even).
COMMON COLLOCATIONS:
- トントンと叩く: to knock/tap rhythmically
- 収支がトントン: income and expenses are balanced
- トントン拍子に進む: to progress smoothly (related expression)