What is the meaning of the word "weight"?

Definitions:

a statistical coefficient assigned to elements of a frequency distribution in order to represent their relative importance noun
- The weight placed on harmful outcomes was far larger than the weight placed on cost.
a unit used to measure weight noun
- They placed two weights in the scale pan.
an oppressive feeling of heavy force noun
- bowed down by the weight of responsibility
the relative importance granted to something noun
- Their opinion carries great weight.