The Abame oracle says that white men will come like locusts and that they will spread destruction. The meaning of this is that, just like locusts do, white men will bring no good to the village.
The underlined word of the sentence which "conclusive" would have a denotation of "impossible to disprove" as it is used in the sentence. Furthermore, a denotation is the "literal" meaning of a word or some may refer to it as the "dictionary definition or meaning."