C15: from Latin condēnsāre, from dēnsāre to make thick, from dēnsusdense
Word Origin and History for condense
v.
early 15c., from Middle French condenser (14c.) or directly from Latin condensare "to make dense," from com-, intensive prefix (see com-), + densare "make thick," from densus "dense, thick, crowded," a word used of crowds, darkness, clouds, etc. (see dense).