All the labour of man is for his mouth, and yet the appetite is not filled. Ecclesiastes 6:7 (KJV)
The word of ‘appetite’ is translated from נֶפֶשׁ nephesh. Its literal meaning is ‘a breathing animal, i.e., an animal of vitality.’ (H5315)[1] But it seems it is used figuratively here, i.e., appetite, desire, greedy, lust, et cetera, or straightforward as a soul, living being, life, self, person, et cetera. The commentators mostly suggest perhaps Qoheleth is referring to ‘death,’ or death’s appetite. But in an overall, this specific verse seems to sum up the madness of labouring under the sun. (Provan, 148)
Reference:
Provan, I. (2001). Ecclesiastes/Song of Songs: The New Application Commentary, Zondervan
[1] https://www.blueletterbible.org/lexicon/h5315/kjv/wlc/0-1/