intensive study
intensive
/in-ˈten(t)-siv/
adjective
of, relating to, or marked by intensity or intensification: such as
highly concentrated
tending to strengthen or increase; especially : tending to give force or emphasis
noun
an intensive linguistic element
noun
the continuous monitoring and treatment of critically ill or injured patients using special medical facilities, equipment, and services
a designated area in a hospital providing intensive care : intensive care unit —often hyphenated when used before another noun
Many of the sickest patients need intensive care, even to the point of being connected to a mechanical respirator.