(だせい)

だせい
noun
inertia; force of habit; momentum
1. inertia; momentum
the tendency to continue in the same state (physics or figurative)
惰性(だせい)(はし)(つづ)ける。
To keep running on momentum.
(くるま)惰性(だせい)(ころ)がった。
The car rolled on its own momentum.
2. force of habit; routine
continuing something out of habit rather than conscious choice
惰性(だせい)(つづ)けている。
I'm continuing out of habit.
惰性(だせい)(なが)されず、変化(へんか)(おそ)れないことが大切(たいせつ)だ。
It's important not to be carried along by inertia and not to fear change.
惰性(だせい)()()っている。
We're dating out of habit (not passion).
惰性(だせい)仕事(しごと)をしていては成長(せいちょう)しない。
You won't grow if you work just out of habit.

惰性(だせい) describes continuing without active effort, either physical momentum or habitual behavior.

KANJI BREAKDOWN:

  • () (lazy, idle)
  • (せい) (nature, tendency)

SENSE 1 (PHYSICAL):

  • Physics term for inertia/momentum
  • Objects continuing in motion
  • 惰性(だせい)(はし)る (coast, roll on momentum)

SENSE 2 (HABITUAL):

  • More common usage
  • Doing things without thought or enthusiasm
  • Often negative connotation (implies lack of motivation)

COMMON EXPRESSIONS:

  • 惰性(だせい)で (out of habit, on momentum)
  • 惰性(だせい)(なが)される (to be carried along by inertia)
  • 惰性(だせい)(つづ)ける (to continue out of habit)

COLLOCATIONS:

  • 惰性(だせい)仕事(しごと)をする (work out of habit)
  • 惰性(だせい)()()う (date out of habit)
  • 惰性(だせい)()ける (give in to inertia)
  • 惰性(だせい)()()る (break out of routine)

NUANCE:

  • Usually implies lack of passion or purpose
  • Suggests need for change or reflection
  • Common in self-help and motivation contexts

RELATED TERMS:

  • 慣性(かんせい) (inertia - physics term)
  • 習慣(しゅうかん) (habit - more neutral)
  • マンネリ (being in a rut)

REGISTER: Neutral. Common in both casual and formal contexts.