Hebel הֶבֶל means "vapor or breath," an important metaphor for something that is short-lived or ephemeral. This word in Eccl 1:2 is translated variously. What do you think is the best translation or how can you translate Eccl 1:2 in your way? More importantly, what is the meaning of "hebel" in Ecclesiastes? That is a matter of interpretation. See below a few examples of English translation:
NRSVue (NRSV updated edition):
Vanity of vanities, says the Teacher,
vanity of vanities! All is vanity.
NIV (New International Version):
“Meaningless! Meaningless!”
says the Teacher.
“Utterly meaningless!
Everything is meaningless.”
CEB (Common English Bible):
Perfectly pointless, says the Teacher, perfectly pointless.
Everything is pointless.
NASB (New American Standard Bible):
“Futility of futilities,” says the Preacher,
“Futility of futilities! All is futility.”
CJB (Complete Jewish Bible):
Pointless! Pointless! — says Kohelet —
Utterly meaningless! Nothing matters!