When ice has unknowingly clumped together in the bottom of a drink container and spontaneously comes free only when the glass is tipped all the way back, giving the drinker an unavoidable cold splash of beverage and ice to the face.

This most commonly happens on a first date or when first meeting someone you're attracted to. Not exactly the (ahem) icebreaker you were looking for.
Hi nice to meet you Emily, my name is Patrick. Oh, so thirsty from working out all afternoon. (Gulp, gulp... Splash!).

Oh Patrick, you just had an ice dam! Let me help you dry off your half shirt.
by Bradlecat April 30, 2008
Get the ice dam mug.
Roof top ice dams destroy millions of dollars worth of property annually. As snow on your roof melts, ice dams form at the roof edges and gutters (also known as icicles). As more snow melts, water gets trapped behind the ice dams. As the trapped water grows it begins moving upward inside the roof shingles and leaks into the house. The short term effect is mold. The longer term effects include, structural damage, ceiling damage, household goods damage, premature roof failure, and flood damage.
We had to use ice melt socks to open channels in the roof ice dam so water could drain off the roof instead of dripping into the ceiling.
by rodmom February 4, 2010
Get the Roof Ice Dam mug.