entrenchment

en|trench|ment /ɪntr'entʃmənt/ (entrenchments)
1 [N-COUNT] usu pl
Entrenchments are a series of long deep holes called trenches which are dug for defence by soldiers in war.
2 [N-UNCOUNT]
Entrenchment means the firm establishment of a system or your own position in a situation.
...the entrenchment of democratic norms.