To increase over a period of time; to accumulate(verb)
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Use "heap up" in a sentence
"What, then, will become of their building who heap up all sorts of rubbish to make a house for the,"
"I learn that Jacob Thomas has gone to the Yankees that is heavy work I would rather cut my throat that to be so treacherous and heap up such a stigma on my family but these are strange times, hard to fathem depths"
"Now it is proposed to heap up all the old traditions, the Gai Savoir, the glory of the Troubadours, the old language, the old customs, and burn them on a pyre."