clathrate
Concise Oxford English Dictionary © 2008 Oxford University Press:
clathrate /ˈklaθreɪt/
▶noun Chemistry a compound in which molecules of one component are physically trapped within the crystal structure of another.
– origin 1940s: from L. clathratus, from clathri ‘lattice-bars’.
'clathrate' also found in these Oxford entries:

