jigger

Jigger is a term with several distinct meanings. It is most commonly associated with a small measuring device used to portion spirits in bars, but it also refers to a parasitic flea, a unit of liquid measure, and a verb meaning to tamper or rig something.

In bartending, a jigger is typically a two‑sided vessel made of metal or glass. The larger side usually holds 1.5 US fluid ounces (44 ml), while the smaller side is about 0.75–1 ounce (22–30 ml). Sizes vary by country and venue, and some sets include additional marks or different pairings to suit specific recipes.

In tropical health contexts, jigger denotes the flea Tunga penetrans, also called the jigger or sand flea. It burrows into the skin, causing tungiasis, and is a public health concern in parts of Africa, the Caribbean, and South America. Prevention focuses on personal protection and environmental sanitation.

As a verb, to jigger means to tamper with or rig something, or to improvise in a clumsy or deceitful way. The term can appear in phrases such as jiggering measurements, jiggering statistics, or jiggering a mechanism to obtain a desired result.