献血
to allow a trained person to take some blood from your body so that it can be stored and is ready to be given to people who have lost a lot of blood in an accident or operation
Essentially, giving blood is about saving lives.
People were lining up in the hundreds to donate blood.
I've been giving blood for over twenty years now.
They provided drinks and snacks for people who were donating blood.
They urged people to report to local hospitals to donate blood.
I like to give blood because I think it's the right thing to do.
See also: blood noun (LIQUID)