Final answer:
Oliguria is a condition characterized by a urine output of less than 500 mL/day. It can be caused by various factors such as fever and dehydration. Oliguria indicates a decrease in urine production.
Step-by-step explanation:
The condition of a urine output of less than 500 mL/day is called oliguria. Oliguria can be seen in various conditions such as fever, shock, vomiting, and diarrhea. It indicates a decrease in urine production and can be caused by dehydration or renal disease.