Select the option that can be used as a one-word substitute for the given group of words.
Weak and cowardly

The correct option is Pusillanimous.

Let us analyze the definitions of the provided options to determine the best one-word substitute for "Weak and cowardly":

1. Pusillanimous: This adjective means showing a lack of courage or determination; cowardly, faint-hearted, or timid. It directly combines the elements of being weak-willed and lacking bravery.
2. Meek: This refers to being quiet, gentle, and submissive, or easily imposed upon. It does not necessarily denote cowardice.
3. Timid: This means showing a lack of courage or confidence, or being easily frightened. While close, "pusillanimous" is a more precise and formal term specifically indicating a contemptible lack of courage.
4. Anxious: This means feeling worry, nervousness, or unease, typically about an imminent event or something with an uncertain outcome, which is distinct from being cowardly.

Thus, Pusillanimous is the most accurate one-word substitute for "Weak and cowardly".