c 3 o 1 l 1 l 1 a 1 b 3 o 1 r 1 a 1 t 1 i 1 o 1 n 1 i 1 s 1 m 3
16 letters · 22 points in Scrabble
Meaning
noun act of cooperating traitorously with an enemy that is occupying your country
originFrom collaboration + -ism.
Etymology from Wiktionary, CC BY-SA 3.0