To fail to be completed, particularly for lack of interest; to be left out.(verb)
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Use "fall by the wayside" in a sentence
"If the young men of the present generation were called on to endure the same experience - which God forbid - they would note disgrace their ancestors, but the topers, the cigarette smokers and the gamblers would play out of the game, just as they fall by the wayside in their battles of banking, rail-roading, merchandising, law, farming, and medicine, and just as they did in 61-65."
"As days turned into weeks, men began to fall by the wayside by the hundreds, then thousands, from sickness, heatstroke, and thirst."