Wiktionary
adv. (context idiomatic English) If necessary; if there is a need. alt. (context idiomatic English) If necessary; if there is a need.
Usage examples of "if need be".
I could do your company some good, lending you the use of my sword if need be, and acting as a guide for some of the trickier parts of the journey yet to come.
And as soon as Marguerite was finished, he could start looking for some stuff for himself, perhaps asking Mephistopheles for an advance on his reward, if need be.
That last was several coins of the Roman period, plus a small ingot he could exchange if need be.
He did not touch the hilt of his sword, but he adjusted his stance so he could reach it quickly, if need be.
All she knew was that she would follow this treasure to the edge of the world, and if need be, over it, if only it brought her back to him again.
I resolve to tear this ship beam from beam, if need be, and locate the captain.
But, unlike the cavalry of other armies, Gustav's men were cross-trained to serve as artillery or even, if need be, as infantry.
When he has finished drinking from that, he feels strong enough to go back and carry the Okinawan boy here, if need be.