Noun
いたみどめ
彼は痛み止めを飲んで、また畑を耕し始めた。
He took a painkiller and kept plowing the field.
痛み is "pain." 止める is "to stop." What stops pain if you use it? How about a painkiller.
The reading is 痛み and 止める put together into one word. Not too painful, right? Just remember the rendaku on the ど.