Whistle

Whis·tle (wĭs′əl, hwĭs′-) n. The unit of measurement for kratom dosage. A "whistle of kratom" or simply a "whistle" is a moderate dose of kratom that is equivalent to approximately 2.5-3 grams of powdered kratom. The slang is mainly used in the Midwest and West of the United States. The term has been said to originate from a technique of powdered kratom ingestion which aims at reducing the tasting of the powder. A whistle is a dose that makes for a successful ingestion of the drug using this technique without feeling the strong taste or smell of the kratom. Such an administration is "clean as a whistle", hence the name.