Definition of sap:

part of speech: noun

The art of approaching a fortress, when within range of fire, by excavating trenches in such a manner as to protect the men from fire.

part of speech: verb

To subvert by digging or wearing away; to mine or undermine; to proceed by mining; to proceed secretly; to undermine, as one's reputation.

part of speech: noun

The vital juice or circulating fluid of plants.

Usage examples:

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