The saturated hydrides of tervalent bismuth, having the general formula $\ce{Bi_{n}H_{n+2}$. Hydrocarbyl derivatives of $\ce{BiH3}$ belong to the class bismuthines.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1322 [Terms] [Paper]