0 the need for something: --
You can come early if you want to, but there's no necessity for it.
[ + to infinitive ] Is there any necessity to reply to her letter?
The report stresses the necessity of eating plenty of fresh fruit and vegetables.
With a personal fortune of sixty million dollars, she certainly doesn't work out of necessity (= because she needs to).
We'll employ extra staff to help out as and when the necessity arises (= when we need to).
1 the need for something, or something that is needed: --
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
We kunnen het stap voor stap voltooien, hoe lang de weg ook is en het kan niet worden voltooid, hoe kort de weg ook is, als je niet eens je voetafdruk markeert.