I thought there was a time limit. There is not a time limit.
Clocks ? ? ?
Clocks are used to show scores higher than 10. Any word that takes 11, 12, or 13 guesses will be displayed as a clock. One reason for this is because there are no emojis for 11, 12 or 13, so a clock showing 11 o'clock, 12 o'clock, and 1 o'clock (13 in a 24 hour clock) is used instead.
Another reason is because clocks indicate time, and the 11th, 12th and 13th guesses are the last guesses you have and so the time pressure is high!