To drain, suck or absorb from (tree, etc.).
To exhaust the vitality of.
To strike with a sap (with a blackjack).
To subvert by digging or wearing away; to mine; to undermine; to destroy the foundation of.
To pierce with saps.
To make unstable or infirm; to unsettle; to weaken.
To gradually weaken.
he saps my energy
To proceed by mining, or by secretly undermining; to execute saps.
The act by which something is sapped or depleted.
The act of excavating trenches.