degree of стар (star, “old, mature”) + -ейш (-ejš). IPA(key): [stɐˈrɛjʃ] <span class="searchmatch">старе́йш</span> • (staréjš) (not comparable) (poetic, obsolescent) senior, of high rank...
By surface analysis, <span class="searchmatch">старе́йш</span> (staréjš, “senior”) + -ина (-ina). IPA(key): [stɐˈrɛjʃinɐ] старе́йшина • (staréjšina) m senior officer (military rank) (obsolete)...