confounding

"The floodwaters damaged many homes in our town. "

"The complicated instructions for the science project completely confounded the students. "

"He discovered penicillin largely accidentally."

"to compound a medicine"

"The river overflowed the levee."

"You need to learn to be more tolerant of difference."

"Given that "indistinguishable" is an adjective, not a noun, here's a sentence using it correctly as an adjective: "The twins were so alike that their voices were almost indistinguishable." "

"Hooligans destroy unprovoked."

"The association of the students with the school's environmental club was evident in their increased recycling efforts. "

"I have forgotten most of the things I learned in school."

"The explanation was long and drawn-out."

"The impossible of finishing the project by Friday became a reality when everyone worked late. "