(set phrase, figuratively) Used as a reminder or warning regarding an impending deadline.

(chemistry) Any of a set of structural isomers that are related by a pericyclic reaction

(idiomatic) You need to see something to believe it; visible facts cannot be denied. / (idiomatic) I am skeptical about your claim.

(physics) A system that does not interact with its surroundings. Depending on context this may mean that its total energy and/or momentum stay constant. In thermodynamics, isolated is usually used to indicate that the system's energy does not change. In mechanics it is used to indicate that the system's momentum does not change.

Finished. There is nothing more to the issue.

An area of roadway from which traffic is excluded so as to provide safety for pedestrians; a traffic island.

(informal, astronomy, archaic) A galaxy

Revenge is best or most satisfying when delayed.

Everyone makes mistakes.

A kiwi, Apteryx mantelli or Apteryx australis.