hard, wearying labor, and by extension the earnings, produce, or property that such labor yields
The word names hard, tiring work and, just as often, what that work produces. Hebrew slides easily from the sweat of labor to the harvest, wages, or wealth it earns, because to an ancient farmer or herder the two were inseparable: your toil simply was your bread.
In its first shade it is the effort itself. Jacob points to "the toil of my hands" that God saw during his hard years working for Laban (Genesis 31:42), and an ostrich labors over eggs she then abandons, so "her toil is in vain" (Job 39:16).
Far more often the word points past the work to its yield: the food a household eats (Psalm 128:2), the crops locusts devour (Psalm 78:46), the wealth of Egypt (Isaiah 45:14), or the earnings strangers plunder (Psalm 109:11). This is why context matters so much: rendering it "labor" everywhere can mislead, since when the text says locusts ate their "labor" it means their crops, not their effort.
A near neighbor is עָמָל, labor felt as trouble and misery, while the verb יָגַע of the same root describes toiling to the point of exhaustion.