Umar

Sadly, this name has NO meaning. Or, alternatively, the original meaning was lost. A look through the Arabic dictionary finds the simple definition that UMAR is a name, no meaning attached. There are many many words constructed by the same consonants ("umr" as you mention) yet there is no relation necessarily between these words, AAMER, AMAR, AMR, UMUR, AMMAR for example have completely different and unrelated meanings. So you cannot associate UMAR with any of these.