/
kəˈlabəreɪt/
v.
  - work jointly on an activity or project.
 - cooperate traitorously with an enemy.
 
Derivative
- collaboration n.
  - collaborationist n. & adj.
  - collaborative adj.
  - collaboratively adv.
  - collaborator n.
 
Etymology
C19: from L. collaborat-, collaborare ‘work together’.