Which word could describe someone who enjoys life fervently?

The term "zest" perfectly captures the essence of someone who enjoys life fervently. It conveys a sense of enthusiasm, energy, and a passionate approach to experiences, emphasizing an eagerness to embrace all that life has to offer. A person described as having zest embodies a lively spirit and a positive outlook, often engaging fully in activities with joy and excitement.

In contrast, the other words do not convey the same vigor for life. "Pensive" typically refers to someone who is deep in thought, often with a melancholic or reflective quality, lacking the enthusiasm that "zest" implies. "Ponderous" describes something that is heavy or dull, often associated with a slow or laborious manner, which is quite the opposite of enjoying life fervently. "Amalgamate" refers to the process of combining or merging, and does not pertain to an individual's enjoyment or attitude towards life. Thus, "zest" stands out as the ideal descriptor for someone who passionately embraces life's experiences.