regret · spare

1. Origins, structure, and basic meaning

• Structure: 惜 has 11 strokes, the on-reading せき, and the kun-readings おしい and おしむ. 惜しい (おしい) expresses regret or a sense that something is too good to waste.
• Basic usage: 惜しい describes a regrettable result or something wasteful to discard; 惜しむ (おしむ) means to regret parting or to spare something.

2. Common pitfalls and similar expressions

• A regrettable result and sparing nothing
  • 一点差で負けたのは本当に惜しかった means that losing by one point was truly regrettable. まだ使える紙を捨てるのは惜しい means that throwing away usable paper would be a waste.
  • 恩師との別れを惜しんだ means that people were sad to part with their former teacher. 材料を惜しまず describes using plenty of ingredients without trying to spare them.