noun
grain sampler; rice thief
A pointed tool inserted into a rice bag to extract a sample; also refers to the person using it. The 'thief' gloss is metaphorical, as it 'steals' a bit of grain.
米刺しで袋から米を抜き取って品質を調べる。
They use a grain sampler to extract rice from the bag and check its quality.
昔の米問屋では米刺しが重要な道具だった。
In old rice wholesalers, the grain sampler was an important tool.
Compound of 米 (こめ, rice) and 刺し (さし, piercing/stabbing), from the verb 刺す (さす, to pierce). The tool is named for its action of piercing into a rice bag to extract a sample.