Which word is synonymous with having a small amount?

The word "meager" is synonymous with having a small amount, as it specifically describes something that is lacking in quantity or quality. For instance, a meager meal would suggest that it is insufficient or not abundant. The term often implies a sense of inadequacy or scarcity, making it the most appropriate choice for expressing a reduced amount.

The other options do not hold the same meaning: "ghastly" refers to something shockingly frightful or dreadful, "inquisitive" denotes a tendency to ask questions or inquire about things, and "tumultuous" describes a state of chaos or disorder, often in relation to noise or disturbance. Therefore, "meager" stands out as the only word that accurately conveys the idea of having a small amount.