Undetected synonyms and antonyms

On the 11th of January 1805 Admiral Missiessy left Rochefort with 5 sail of the line, undetected by the British forces on the coast.

Now, whether a real, though undetected, change occurs is a question to be determined from case to case; it is certain, however, that a substance like aragonite (a mineral form of calcium carbonate) has sensibly persisted in geological periods, though the polymorphous calcite is the more stable form.

The aim in the game is to go undetected.

This deadly affliction can remain undetected for months, until infected animals are subject to a number of uncomfortable and potentially fatal conditions.

Some mild cases may be undetected, with no abnormalities present except infertility.