# import necessary libraries
import pandas as pd
# define your series
series = pd.Series(['apple', 'banana', 'cherry', \
'plum', 'orange'])
# create custom function
def has_two_vowels(word):
word = word.lower()
vowels = [char for char in word \
if char in 'aeiou']
if len(vowels) >= 2: return word
# use apply() to apply the function
words = series.apply(has_two_vowels).dropna()
# print filtered words
print(words.to_list())