The Clock is now recognized as a universal symbol of the nuclear age.
I think they felt that the cross was a universal symbol.
The American flag is a universal symbol of liberty and democracy.
I stretched out my arms, making the universal symbol for "this much."
A boar's head is the universal symbol of the main course.
You're right in your statement that the cross is a universal symbol for Christ's death.
Allegedly this is the world's only universal symbol set for maps.
The notion of a heart representing the word "love" spread quickly and has become a universal symbol.
It is the single universal symbol of all magic, good or evil.
The question mark is the universal symbol of something unknown.