ne ‧ ces ‧ si ‧ tate /nəˈsesəteɪt, nɪˈsesəteɪt/ BrE AmE verb [transitive] formal
[ Word Family: noun : ↑ necessity , the necessaries, the necessary; verb : ↑ necessitate ; adverb : ↑ necessarily ≠ ↑ unnecessarily ; adjective : ↑ necessary ≠ ↑ unnecessary ]
to make it necessary for you to do something:
Lack of money necessitated a change of plan.
necessitate doing something
This would necessitate interviewing all the staff.