In a strict sense, the silyl radical is $\ce{H3Si^{.}}$.
A name commonly applied to the silicon-centered radicals $\ce{R3Si^{.}}$.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1366 [Terms] [Paper]