We have the word "eternal" that refers to something that will exist forever, something that never ends, which is related to the word "eternity" that refers to the end of time.
Is there a similar word for "the beginning of time", or something that has existed, as some might say, "since forever"? As an adjective, it would be used like: "My love for you is …". The noun could be used like: "I have loved you since …".
There is such a Persian word, for example, widely used in Persian literature, which is usually used to describe God, Love, etc.
Best Answer
Eternal does not refer to the "end of time." Eternal means "outside of time."
See Oxford
Something that has existed "since forever" is eternal. It is outside of time and did not have a beginning.
Consider the cosmos. If it did not have a beginning, but has always existed, then it is eternal. If it had a beginning, it has not existed forever.
Adjective: eternal. My love for you is eternal.
Noun: Does not compute. You cannot use a 'time-word' such as "since" to refer to the eternal or eternity. However, you may simply replace "since" with "for". "I have loved you for eternity."
You can refer to "the beginning of time". "In the beginning, God created...", or "In the beginning, the Uncaused Cause caused...". On the other hand, you can't refer to "(Before) the beginning of time", because time came into existence along with the cosmos. Outside of time stands eternity.