Based on the description provided, the secret words in the game "Cemantik" are everyday, simple, and well-known terms. The game involves guessing these words by proposing various answers, which are then scored based on their contextual similarity to the secret word. The secret words are singular unless their plural form is more commonly used.

Here are some examples of what the secret words might be, considering they are simple and well-known:

1. Dog - A common household pet, often used in everyday conversation.
2. House - A familiar term for a place where people live.
3. Tree - A well-known natural object found in many environments.
4. Car - A common mode of transportation.
5. Book - A widely recognized object used for reading.

These examples are based on the criteria mentioned: they are simple, singular (unless the plural is more common), and well-known. The actual secret words would vary daily and could be different from these examples, but they would follow the same general guidelines.