Entrenchment (noun)

1. The act or process of fortifying a position, especially by digging trenches or other protective barriers.
2. The act of digging a trench as a means of defense.
3. The establishment or strengthening of an idea, belief, or custom.
4. A position that is firmly established or difficult to change.

Origin:

From the old french word "entrenchier", meaning "to fortify, dig a trench".

Examples:

1. The entrenchment of the soldiers provided some protection from enemy fire.
2. The entrenchment of the fortress was a formidable barrier to invading forces.
3. The entrenchment of the company's policies made it difficult for employees to suggest changes.
4. The entrenchment of old-fashioned attitudes was a hindrance to progress.
5. The entrenchment of their beliefs made it difficult for the two political parties to reach a compromise.