The concept or quality that defines something at its very core.(noun)
The intestines.(noun)
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Use "bowels" in a sentence
"Fastened to the sides of the winding tunnels, the tubes gave new visual meaning to the phrase "bowels of the Earth.""
"We English even, fastidious as we are, employ the term bowels as a natural symbolization for the affections of pity, mercy, or parental and brotherly affection."
"Mrs Wilson has had an inflammation in her bowels, is recovered, and gaining strength."