from
The Collaborative International Dictionary of English v.0.48
Sap \Sap\, v. t. [imp. & p. p. {Sapped}; p. pr. & vb. n.
{Sapping}.] [F. saper (cf. Sp. zapar, It. zapare), fr. sape a
sort of scythe, LL. sappa a sort of mattock.]
1. To subvert by digging or wearing away; to mine; to
undermine; to destroy the foundation of.
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Nor safe their dwellings were, for sapped by floods,
Their houses fell upon their household gods.
--Dryden.
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2. (Mil.) To pierce with saps.
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3. To make unstable or infirm; to unsettle; to weaken.
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Ring out the grief that saps the mind. --Tennyson.
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