Answer
$CH_3COO^-$ is a weak base;
Conjugate acid: $CH_3COOH$, which is a weak acid.
Work Step by Step
$CH_3COO^-(aq) + H_2O (l) --> CH_3COOH(aq) + OH^-(aq)$
As we can see, $CH_3COOH$ is the conjugate acid of $CH_3COO^-$.
Since $CH_3COO^-$ is a weak base (but not insignificant), his conjugate acid will be weak too.
