birr vs tiredness

birr

• To make a whirring noise; make a noise like that of revolving wheels, or of millstones at work. 

• To lurch or set to spinning. 

• The currency of Ethiopia, divided into 100 santims. 

• A strong trilling. 

• The force of movement; rush, impetus, momentum, driving force 

• A whirring noise 

• strength, vigor, energy 

tiredness

• The state of being tired.