Try tkinter or pygame for making a basic GUI. Makes it more user friendly than ipynb and terminal. Another good exercise.

Make sure game logic is correct before you do anything else!

For example, if I've guessed a letter, I shouldn't be allowed to guess it again. That's unnecessary penalizing. Do more input validation other than checking 'a-z'. Think that the user may be able to press any key they want so make sure your program can react accordingly.

In extension to that, check out #3

Try to introduce game options like 'easy/medium/hard' if possible, and other such variations that you may be able to bring about in a hangman game just for variability.

PEP8 is a standard for styling for python code. This may not even be an existent issue, but just check it out for yourself

Minor issues that you can ignore for the time being, but I feel they might be better practices

cond='y'

while(cond=='y'):
    if meaning=="'ISO 639-6 entity'":
        word, meaning = random.choice(list(data.items()))
        meaning=str(meaning).strip('[]')
        for l in word:
            if l not in validLetters:
                word, meaning = random.choice(list(data.items()))
                meaning=str(meaning).strip('[]')
    else:
        cond='n'

Instead of using 'cond' var, you can just use a while True and get it done

if turns == 9:
                print("9 turns left")
                print("  --------  ")
            if turns == 8:
                print("8 turns left")
                print("  --------  ")
                print("     O      ")

and so on...

You can easily condense this code in the loop and avoid rewriting statements whenever possible, you can try to reuse it, or relate it with the loop counter, for example, print(turns, "turns left") so that saves a lot of lines just like that. Think of a logic to condense that code and put it on a loop.

Give the user an option to either fetch dictionary words online if they have an internet connection, or they can download the dictionary if they want to play offline. It's not a big deal, but I want you to try out something new, i.e. how to fetch info from the internet thru a python script. Fetching dictionary from the internet may even give rise to more opportunities from there.

Extension of #2