The Hebrew word amal functions as both a verb (to toil, labor strenuously) and a noun (toil, labor, trouble, misery). It occurs about 55 times in the Old Testament, with heavy concentration in Ecclesiastes (where it defines the vanity of human effort) and the Psalms (where it describes wickedness and oppression).
Amal captures the exhausting, often futile quality of human labor under the curse. Ecclesiastes uses it repeatedly to describe the 'toil' under the sun: all human striving — work, wisdom, pleasure, achievement — is amal, toil that ultimately amounts to nothing without God (Ecclesiastes 1:3; 2:11). Yet the Psalms use amal differently: Psalm 90:10 (Moses's psalm) calls the years of our life 'trouble and sorrow,' while Psalm 107 contrasts the toil of the afflicted with God's redemption. Habakkuk 1:3 uses it for social injustice — 'Why do you make me look at amal?' The word thus spans from existential meaninglessness to social evil to the honest hardship of a life lived faithfully.