This is the 3886th most frequent Portuguese word.
elena
"Elena" is a proper noun, typically a given name, and does not have a specific definition in Portuguese beyond being a name.
In this sentence, 'Elena' is used as a proper noun, specifically a name referring to a person.
Elena é uma óptima amiga.
Elena is a great friend.
Here, 'Elena' again functions as a proper noun identifying a specific person.
Elena parece estar cansada hoje.
Elena seems to be tired today.
In this case, 'Elena' continues its role as a proper noun used to identify an individual in conversation.