Each guess must be a word (or short phrase like San Juan or id est). Elmantle will tell you how semantically similar it thinks your word is to the secret word. Unlike that other word game, it's not about the spelling; it's about the meaning. The similarity value comes from Word2vec. The highest possible similarity is 100 (indicating that the words are identical and you have won). The lowest in theory is -100, but in practice it's around -34. By "semantically similar", I mean, roughly "used in the context of similar words, in a database of news articles."
Secret words may be any part of speech, but will always be single words. It's tempting to think only of nouns, since that is how normal semantic word-guessing games work. Don't get caught in the trap! Since our Word2vec data set contains some proper nouns, guesses are case-sensitive. But I removed all but lower-case words from the secret word set, and if your word matches the secret word but for case, you win anyway. So if you want to know if the word is more like nice or Nice, you can ask about both.
The "Getting close" indicator tells you how close you are --if your word is one of the 1,000 nearest normal words to the target word, the rank will be given (1000 is the target word itself). If your word is not one of the nearest 1000, you're "cold". (By "normal" words", I mean non-capitalized words that appears in a very large English word list; there are lots of capitalized, misspelled, or obscure words that might be close but that won't get a ranking. Those get marked with "????").
You will need more than six guesses. You will probably need dozens of guesses. There's a new word every day, where a day starts at midnight UTC .