The appearance of "fetus" was "entirely unintentional and a coincidence", the newspaper said in a message to readers on Monday.
"At New York Times Games, we take our role seriously as a place to entertain and escape, and we want Wordle to remain distinct from the news," the message said.
The Times changed Monday's answer to a different word, and a spokesman said that a "vast majority" of users saw that. But some people who had not refreshed their browsers saw "fetus" instead, spokesman Jordan Cohen said.
Many users in New Zealand reported seeing the word.
Cohen would not say whether the Times had received any complaints about "fetus".
Wordle was invented by Josh Wardle, a Brooklyn software engineer, as a gift for his partner and took off when he began posting it online. Players guess words and hone in on the correct answer as the game tells them if their guesses contain letters in the word of the day.
The Times bought his invention for more than US$1 million and is revamping the technology to make sure every user is seeing the same word every day, the newspaper said. Cohen said millions of people play Wordle each day.