If you didn't already know what Hippopotomonstrosesquippedaliophobia was, it's very easy to guess from four options.
I agree there were too many clicks per word, I took me too long to finish. But I also found it too easy to guess the few words I did not know
In particular, I got a bunch of guesses correct because there's a pattern that several options are often related to each other, and either only one is different, (e.g., "Do good", "Do bad", "Be evil") -- in which case the answer is obvious -- or at least there's a contrasting pair which narrows it down to a 50% chance.
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Does the ability to guess the meaning of a word (from four options or context) is the same as knowing the word and using it in your speech?
It is not. Vocabulary is far from the binary of "you know this word or you don't". At a minimum, it is usually split into passive and active vocabulary, with passive being the words you understand when encountered, and active being the words you can use effectively. Wikipedia's entry is a pretty good overview.
It is more like an ability to recognize the word when it is used in context.
I got ~1/3 that is very generous estimate even for "recall" case (recognize), and it obviously false for the "generate" case (using in speech) where I guess my vocabulary is likely ~1/90 of all English words.
No, absolutely not, and that's my point. A real test would be having to type the definition, or pick from ten options
I think that picking the correct (or most correct, which is trickier) use of the word in context (out of, as you say, many options) might be a good way to test for receptive vocabulary.