How do you make a program that prints out a random word in a list and the user has to find the opposite of that word?

My code so far is:

print('Welcome to your ks2 assessment')
print('You will be given a word and you must find the opposite of that word')

print('your assesment has now started, good luck')

wordslist1 = ['hot', 'summer', 'hard', 'dry', 'heavy', 'light', 'weak', 'male', 'sad', 'win', 'small', 'ignore', 'buy', 'succeed','reject', 'prevent', 'exclude']

wordlist2 = ['cold', 'winter', 'soft', 'wet', 'light', 'darkness', 'strong', 'female', 'happy', 'lose', 'big', 'pay' ,'attention', 'sell', 'fail', 'accept', 'allow', 'include']