1. The problem is to find the slope of the linear function given by the equation $y = -5x - 1$. 2. Recall that the slope-intercept form of a line is $y = mx + b$, where $m$ is the slope and $b$ is the y-intercept. 3. In the equation $y = -5x - 1$, the coefficient of $x$ is $-5$, which directly gives the slope. 4. Therefore, the slope of the line is $-5$. The final answer is: $\boxed{-5}$.