1. pivotal
a pivotal role. point or figure in something is one that is very important and affects the success of that thing.
e.g. The court of Appeal has a pivotal role in the English legal systems.
2. notwithstanding
inspite=despite=notwithstanding
e.g. His relationship with colleagues, differences of opinion notwithstanding, were unfailingly friendly.
3. caustic
caustic chemical substances are very powerful and can dissolve other substances.
e.g. Remeber that this is caustic, use gloves or spoon.
