[1] : The Collaborative International Dictionary of English v.0.48

mass \mass\, v. i. imp.  p. p. massed; p. pr.  vb. n.
   massing.
   to celebrate mass. obs. --hooker.
   1913 webster
see also:
massed massing 

[2] : WordNet (r) 2.0

massed
     adj : brought together into a group or crowd; "the accumulated
           letters in my office" syn: accumulated, amassed, assembled,
            collected, congregate
see also:
accumulated amassed assembled collected congregate 

Massed >> M Words
Massed, definition of term: Massed
massed_pag1.html