一いっ生しょうもん

noun

something that lasts a lifetime; high-quality lifelong item

Colloquial noun, often used for durable goods, tools, or products of exceptional quality that one expects to use for life. The suffix もん is a casual contraction of もの.

See also: 一生もの

• この包ほう丁ちょうは一いっ生しょうもんだよ。

  This kitchen knife is something that will last a lifetime.

• いい家か具ぐは一いっ生しょうもんになるから、多た少しょう高たかくても買かう価か値ちがある。

  Good furniture becomes a lifelong item, so it's worth buying even if it's a bit expensive.