arrow of time

Etymology
Reported coined in 1927.

Noun

 * 1)  The direction of time within a four-dimensional relativistic view of the cosmos.
 * 2)  The subjective feeling of movement from past to future.
 * 3) Entropy.

Translations

 * Finnish: ajan nuoli
 * Polish: strzałka czasu
 * Portuguese: seta do tempo
 * Romanian: săgeata timpului