Frontal lobes refer to the area of the brain located at the front of each cerebral Hemisphere which is responsible for the functions underlying much of our thinking and reasoning abilities, including memory.
Other /More definition:
Frontal lobes refers to the area of the brain located at the front of each cerebral hemisphere; responsible for the functions underlying much of our thinking and reasoning abilities, including memory; it is also associated with movement, the sense of self, and higher mental functions.

Moreover, Frontal lobes is a part of the human brain which are associated with executive functions such as formulating, planning, and carrying out goal-directed behavior, monitoring and controlling behavior, and modulating emotions.