"Toothache" is the Engpsh word for "牙痛." It is a noun that refers to pain in the teeth or surrounding tissues, such as the gums. The word "toothache" is a compound word made up of two smaller words: "tooth," which refers to one of the hard, bony structures in the mouth used for chewing, and "ache," which refers to a continuous, dull pain.

The word "toothache" has been used in Engpsh for centuries, and it can be found in many different contexts. Here are a few examples of sentences that use the word "toothache," along with their translations into Chinese:

"I have a terrible toothache. It's keeping me up all night." (我牙痛得厉害。它让我整晚都睡不着。)
"The dentist gave me some painkillers for my toothache." (牙医给我了一些止痛药来缓解我的牙痛。)
"I can't eat anything cold because it makes my toothache worse." (我不能吃任何冷的东西，因为它会让我的牙痛更加严重。)