Learner's definition of UNIT
1 : a single thing, person, or group that is a part of something larger
The family is the basic unit of society.
The search party broke up into smaller units.
Their army unit guarded the border.
2 : a part of a hospital where a particular type of care is provided
the intensive care unit
a trauma unit
3 : a particular amount of length, time, money, etc., that is used as a standard for counting or measuring 4 : a part of a school course or textbook with a particular subject 5 US, education : an amount of work used for measuring a student's progress towards earning a degree in a school, college, etc. 6 business : an individual item of one of the products that a company makes and sells 7 : a machine or part of a machine or system that has a particular use 8 : one of a number of apartments in a building 9 : a set of similar pieces of furniture (such as shelves or cabinets) that are grouped or attached together