v.
  
/
ˈkjuːmjʊleɪt/
  
- accumulate or be accumulated.
 - 
[as adj. cumulated]
 Chemistry  denoting two double bonds attached to the same carbon atom.
 
n.
  
/
ˈkjuːmjʊlət/
 
Geology  an igneous rock formed by gravitational settling of particles in a magma.
 
  Derivative
  
  Etymology
  C16 (in the sense ‘gather in a heap’): from L. cumulat- cumulare, from cumulus ‘a heap’.