赤身

1. Origins, structure, and basic meaning

• Structure: 赤身 (あかみ) is a compound noun for the lean, reddish flesh of meat or fish.
• Basic usage: 脂の少ない赤身の肉 modifies a lean cut of meat, while まぐろの赤身を厚く切る makes tuna’s red flesh the object sliced thickly.

2. Common pitfalls and similar expressions

• Lean meat and tuna cut
  • 赤身の肉 contrasts meat with fat, whereas まぐろの赤身 is a specific fish cut. The noun does not denote every red-colored ingredient.