unannounced

adj

Etymology: Etymology tree Proto-Indo-European *né Proto-Indo-European *n̥- Proto-Germanic *un- Proto-West Germanic *un- Old English un- Middle English un- English un- English announced English unannounced From un- + announced.

1. Not announced beforehand.

   “But soon one notices, first in ones and twos, and then in larger groups, men who are very much alive at this hour in the morning, the sorters for the Caledonian, and Edinburgh sections of the "Down Special"; mail is piled high on the platforms, and the postal men glance occasionally towards the platform intermediate signals. By this time the calling-on arm is pulled off, and a few minutes later in comes the train, unannounced by the loud-speakers, to the mystification of many travellers.”

   “In 2008, she was at times criticized for being detached from voters, insulated in a bubble of staff and security and avoiding spontaneity. She began her 2016 campaign by riding 16 hours in a van from New York to Iowa, making unannounced stops at gas stations and fast-food restaurants, before arriving for what was billed as a series of low-key conversations with a handful of voters.”