puddle of blood; pool of blood
Refers to a visible accumulation of blood on a surface, often in crime or accident scenes.
There was a puddle of blood on the floor.
There was a large pool of blood at the scene.
Variant with 溜り instead of 溜まり; rare.
Compound of 血 (chi, 'blood') and 溜まり (tamari, 'pool, puddle'), the nominalized form of 溜まる (tamaru, 'to accumulate').