Teamwork obstacle can be described as any barrier that hinders the ability of a team to work together effectively. The two crossword solutions for this term are EGO (3 letters) and ACRIMONY (8 letters). EGO is defined as an individual's sense of self-importance, while ACRIMONY is defined as a feeling of bitterness or ill will. Both of these terms can be seen as obstacles to teamwork, as they can lead to conflict and disharmony among team members.