Cas·i·mir effect 
(kăzə-mîr′)
(kăzə-mîr′)n.
The effect of a net attractive force between objects in a vacuum, caused by the reduction of vacuum pressure in the space between the objects, where the wavelengths of vacuum fluctuations are more limited than in the space around the objects.
[After Hendrik Casimir (1909-2000), Dutch physicist who predicted its existence in collaboration with Dirk Polder (1919-2001), Dutch physicist.]