Words that have TH in the middle:

​

Amethyst
​Toothbrush
​Bathroom
​Mouthful
Withhold​
​Author
Mythology
​Northeast
​Gothic
​Youthful

Athlete
Withdraw
​Bathrobe
Pathway
​Bathtub
Toothache
​Method
​Southwest
Catholic
Ruthless

Cathedral
Mathematics
Monthly
Bathrobe
Toothpaste
Without
Together
Clothing
Southern
Tithing

Brother
Father
Gather
Either
Feather
Leather
Mother
Another
Rather
Weather