DAM

n. & v. --n. 1 a barrier constructed to hold back water and raise its level, forming a reservoir or preventing flooding. 2 a barrier constructed in a stream by a beaver. 3 anything functioning as a dam does. 4 a causeway. --v.tr. (dammed, damming) 1 furnish or confine with a dam. 2 (often foll. by up) block up; hold back; obstruct. [ME f. MLG, MDu.]