The first meaning of the term indispensable mentioned by the Royal Spanish Academy (RAE ) in your dictionary refers to that cannot be dispensed . The verb dispense, meanwhile, refers to surrender or grant; to absolve of a fault; or to exempt from an obligation.
However the concept It usually appears more frequently in its second meaning. The indispensable, in this framework, is what results essential or necessary .
For example: "Cristiano Ronaldo is indispensable in the Portuguese team: without his presence, the team cannot aspire to compete with the powers", “It is not essential to have a car to know the main attractions of the city since the public transport system is very developed and efficient”, "It is essential that the government take measures to reduce inflation because the loss of purchasing power of citizens is increasingly noticeable".
The indispensable can not be avoided or should be missing . Suppose a road is covered with snow: in this situation, it is indispensable that the vehicles carry chains on their wheels The chains act as non-slip, causing the wheels not to skate and, thus, minimizing the risk of accidents. Without chains, however, drivers would lose control.
That a city has parks, squares and groves, on the other hand, is indispensable so that its inhabitants enjoy a good quality of life . Trees and plants help purify the air with the photosynthesis , absorbing carbon dioxide and releasing oxygen. They also generate psychological benefits in people by contributing to tranquility and relaxation. That is why it is essential that buildings and urban development do not threaten vegetation.