unheralded- not heralded; coming or occurring without advance notice (adj)

” There are unheralded tipping points, a certain number of times that we will unlock the front door of an apartment”.

https://www.merriam-webster.com/dictionary/unheralded 

While reading and annotating my copy of “City Limits” by Colson Whitehead, I came across the word unheralded. Although I recognize the word, I wasn’t familiar with the precise definition. My first thought after seeing the word was that the prefix ( un ) means not. I took a good guess that the rest of the word would become a verb once it was separated by that prefix, due to the fact that the “un” made the word and adjective. After finding the correct definition; means unexpected, I now know the definition and feel comfortable using the word in a sentence. If you are still a bit confused, try using the context clues in the article, in paragraph (11), lines 3-5 when Whitehead use words and phrases such as “ if”, “would have” or “ but you had no idea”.