it says 'guess' is not defined. help me

import os
import random
import sys

words = [
    'apple',
    'banana',
    'orange',
    'coconut',
    'strawberry',
    'lime',
    'grapefruit',
    'lemon',
    'kumquat',
    'bluberry',
    'melon'

]

def clear():
    if os.name == 'nt':
        os.system('cls')
    else:
        os.system('clear')


def draw(bad_guesses, good_guesses, secret_word):
    clear()

    print('strikes: {}/7'.format(bad_guesses))
    print('')

    for letter in bad_guesses:
        print(letter, end=' ')
    print('\n\n')    

    for letter in secret_word:
        if letter in good_guesses:
            print(letter, end ='')
        else:
            print('_', end='')

    print('')
    print('strikes: {}/7'.format(bad_guesses))
    print('')

def get_guess(bad_guesses, good_guesses):
    while True:
        guess = input("guess a letter: ").lower()

        if len(guess) != 1:
            print("you can only guess a single letter")
        elif guess in bad_guesses or guess in good_guesses:
            print("you've already guessed that letter")
        elif not guess.isalpha():
            print("you can only guess letters")
        else:
            return guess

def play(done):
    clear()
    secret_word = random.choice(words)
    bad_guesses = []
    good_guesses = []

    while True:
        draw(bad_guesses, good_guesses, secret_word)
        guess = get_guess(bad_guesses, good_guesses)

        if guess in secret_word:
            good_guesses.append(guess)
            found = True
            for letter in secret_word:
                if letter not in good_guesses:
                    found = False
            if found:
                print('you win!')
                print('the secret word was {}.'.format(secret_word))
                done = True
        else:
            bad_guesses.append(guess)
            if len(bad_guesses) == 7:
                draw(bad_guesses, good_guesses, secret_word)
                print('you lost!')
                print('the secret word was {}.'.format(secret_word))
                done = True

        if done:
            play_again = input("play again? Y/n").lower()
            if play_again != 'n':
                return play(done=False)
            else:
                sys.exit()

while True:
    start = input("press Enter to start, or enter Q to return")
    if start.lower() == 'q':
        break

    secret_word = random.choice(words)
    bad_guesses = []
    good_guesses = []

    while len(bad_guesses) < 7 and len(good_guesses) != len(list(secret_word)):

        if guess in secret_word:
            good_guesses.append(guess)
            if len(good_guesses) == len(list(secret_word)):
                print("you win!, the word was {}".format(secret_word))
                break
        else:
            bad_guesses.append(guess)

    else:
        print("you didn't guess it, My secret word was {}.".format(secret_word))

def welcome():
    start = input("press Enter to start or Q to quit").lower()
    if start == 'q':
        print("bye")
        sys.exit()
    else:
        return True

print("Welcome to letter guess!")
done = False
while True:
    clear()
    welcome()
    play(done)