ロス

ろす
noun
loss, waste
1. loss, waste
Waste or loss of resources such as food, time, or materials. Used in compound forms.
フードロスを()らそう。
Let's reduce food waste.
タイムロスが(おお)きかった。
The time loss was significant.
食品(しょくひん)ロスの削減(さくげん)社会(しゃかい)全体(ぜんたい)課題(かだい)だ。
Reducing food waste is a challenge for society as a whole.
2. sense of loss, withdrawal
A feeling of emptiness or loss when something or someone one was attached to is gone. Often used with a person's name or show title as a prefix.
ペットロスがつらい。
The sense of loss after losing my pet is painful.
ドラマが()わって〇〇ロスだ。
The drama ended and I'm feeling withdrawal.
()しが引退(いんたい)して、ロスから()(なお)れない。
My favorite idol retired and I can't recover from the sense of loss.

ロス from English "loss" is used in two main ways in Japanese.

SENSE 1 — WASTE/LOSS:

Used in compound nouns about waste or inefficiency.

  • フードロス / 食品(しょくひん)ロス: food waste
  • タイムロス: time loss
  • ロスを()らす: to reduce waste

SENSE 2 — EMOTIONAL LOSS:

A popular slang usage meaning the feeling of emptiness when something beloved ends or disappears. The trigger is used as a prefix.

  • ペットロス: grief from losing a pet
  • 〇〇ロス: withdrawal from a show/person ending

NOTE:
Sense 2 became widely popular after the 2013 NHK drama あまちゃん ended, with "あまロス" becoming a trending term.