The word "cosmos" is from the Greek "kosmos", meaning "complex order". It is used 186 times in the new testament, and not in reference to the "heavens". It is used to refer to people outside christianity.

John. 18:36; the human race external to the Jewish nation, the heathen world

Rom. 11:12, 15; the world external to the Christian body

The Greek term for "everything" was τὸ πᾶν tò pân ("the all"), although that didn't include "the void".

The word "universe" means literally in Latin, "one turn". In the bible, "universe" is synonymous with "heavens". The word in the old testament for heavens is shamayim, which means the sky. To the ancient Hebrews, anything "up" was "sky", equaling "heavens".

The point of this is the word "cosmos" is being found to be factually incorrect, or mutually exclusive. It was a view that the "heavens" were complex, but they were also supremely uniform. We are directly observing how chaotic the "heavens" are, blowing up, colliding, throwing itself apart, anything but "cosmos" smooth order.

The word "universe" for the "heavens" is more descriptive. One Turn, one shot, YOLO. It is symantics but it affects our cognitive perceptions of the meaning of words applied to the physical phenomena. Cosmology, by virtue of the connotation of the word is about the study of a complicated but smooth "heavens". It would be more descriptive to call it shamayimam-ology, the study of the sky.

The reason this is important is how so many people get fixated on the word "universe". The word "universe" does not mean "the all" or "everything". It means one turn, one shot, one existence, one state of being. Books and titles with "cosmos" actually indicate they don't know what they are talking about.