To find the fifth term of the sequence defined by the function \( f(n) = 2n - 1 \), we need to substitute \( n = 5 \) into the function.
\[ f(5) = 2(5) - 1 \]
Calculating this gives:
\[ f(5) = 10 - 1 = 9 \]
Thus, the fifth term of the sequence \( f(5) \) is \( \boxed{9} \).