The word "erosivities" may seem like a tongue twister, but its spelling is actually quite straightforward when broken down phonetically. The first syllable, "er," is pronounced "er" as in "her." The second syllable, "o," is pronounced "oh" as in "go." The third syllable, "si," is pronounced "siv" as in "positive." Finally, the fourth syllable, "ties," is pronounced "teez" as in "keys." Altogether, the word is pronounced ee-ruh-soh-siv-uh-teez, and refers to the state of being erosive.