What is the meaning of Excelsior?

Loftier, yet higher, more elevated; ever upward.

More surpassing, more excelling.

Onward; a rallying cry for progress.

A greeting, farewell or acclamation.

Excelsior (Longfellow) on Wikipedia.Wikipedia

2023, June 20, Stan Lee and the Story of Excelsior!, The Real Stan Lee]

The size of type between Norse and brilliant, standardized as 3-point.

Stuffing material (as for furniture and mattresses) made of slender, curled woodshavings, as a substitute for hair.

comparative degree of excelsus

Source: wiktionary.org