This is the 1800th most frequent Spanish word.
cerebro
Brain.
Here, 'cerebro' is used to refer to the physical organ that is associated with thinking and processing information.
Mi cerebro está cansado después de estudiar todo el día.
My brain is tired after studying all day.
In this sentence, 'cerebro' is used in a general sense to refer to mental faculties that benefit from stimulation.
Es importante ejercitar el cerebro con actividades cognitivas.
It's important to exercise the brain with cognitive activities.
Here, 'cerebro' is metaphorically used to describe the person responsible for leading or conceptualizing the project.