The type of conclusion which ends with the outcome still unknown is called CLIFF HANGER.
Cliff hanger is a style use in literary works, it involves leaving some questions unanswered in a novel for instance, it is usually done is such a way that the readers will be put in suspense to know the ending of the story.
Cliff hanger is usually used by authors in order to ensure that the readers will be forced to read the sequel editions in order to discover how the book actually end.
The answer to you question is a synonym. Words that have the same meaning.
The tone of a poem reveals the speaker's attitude towards the subject of the poem and towards its audience. In poems, the tone is indicated by using figures of speech, rhyme, sentence structure, and imagery.
Word choice is another resource that poets have to reveal their voice. Word choice refers to the selection of words the poet chooses to use and they determine the message that the poet is trying to convey. It adds style to the work. For example, choosing between abstract or concrete words draws an idea of the poet's style.