Unit means part of something: a ~ in an army/air force, a navy. Component, building block of constructions and molecules.
It could mean a unit of measurement, ~ of currency (£$¥¤€).
Units sometimes means the digit in a number on the right, which is also called the "ones".
In exact sciences use is made of cgs/psi/cal and m kg s/N/J systems. The SI units in calculation and measurement prevail.
Some other ideas come from this word:
- Unity is what is found when parts are joined into one.
- On stage: ~ of place, time and act means unchanged setting.
- Trinity (3 in 1) in theology.
- To unite is the act of joining parts together.
- A football team may be called "X United". This means that the town of X has come together to support the group.
- The UK, USA, UAE; UNO and its organisations.
- ~d we stand, divided we fall. Workers ~ never will be defeated (lengthy piano piece).
In the BBC TV series Doctor Who, UNIT is a military group on earth (UNified Intelligence Taskforce) who battle invading aliens.