The term foot bill is not an actual word, but it could be a combination of two separate terms: "foot" and "bill." Foot means the lower extremity of a leg below the ankle, while the bill means an amount of money owed for goods and services received. Therefore, antonyms for foot could include head, upper body, or arm, while antonyms for bills could include credit, savings, or profit. In conclusion, combining both terms does not create a logical meaning, but understanding the antonyms and opposite meanings of individual words can improve our language comprehension.