What exactly is meant by "partial function" in functional programming?

According to my understanding, partial functions are functions that we get by passing fewer parameters to a function than expected. For example, if this were directly valid in Python:

>>> def add(x,y):
...    return x+y
... 
>>> new_function = add(1)
>>> new_function(2)
3

In the snippet above, new_function is a partial function. However, according to the Haskell Wiki, the definition of partial function is

A partial function is a function that is not defined for all possible arguments of the specified type.

so, my question is: what exactly is meant by "partial function"?

from What exactly is meant by "partial function" in functional programming?