essential (essentials plural )
1 adj Something that is essential is extremely important or absolutely necessary to a particular subject, situation, or activity.
oft it v-link ADJ to-inf
(=crucial)
It was absolutely essential to separate crops from the areas that animals used as pasture..., As they must also sprint over short distances, speed is essential..., Jordan promised to trim the city budget without cutting essential services.
2 n-count The essentials are the things that are absolutely necessary for the situation you are in or for the task you are doing.
usu pl
The flat contained the basic essentials for bachelor life.
3 adj The essential aspects of something are its most basic or important aspects.
(=fundamental)
Most authorities agree that play is an essential part of a child's development..., In this trial two essential elements must be proven: motive and opportunity.
4 n-plural The essentials are the most important principles, ideas, or facts of a particular subject.
...the essentials of everyday life, such as eating and exercise...