泡沫

1. Origins, structure, and basic meaning

• Structure: The written form is 泡沫, read ほうまつ. Elements associated with bubbles combine to denote foam and, figuratively, something fleeting.
• Basic usage: 白い泡沫 is literal foam on waves, while 泡沫のように消える is a simile for the fleeting disappearance of a dream.

2. Common pitfalls and similar expressions

• Literal foam on water
  • White foam is visibly floating on the surface of the waves. Example: 波の表面に白い泡沫が浮かんでいた。 — White foam floated on the surface of the waves.
• A metaphor for transience
  • Their dream is compared to a bubble that vanishes. Example: 彼らの夢は泡沫のように消えてしまった。 — Their dream vanished like a bubble.