Synonym Discussion of essential. essential, fundamental, vital, cardinal mean so important as to be indispensable. essential implies belonging to the very nature of a thing and therefore being incapable of removal without destroying the thing itself or its character conflict is essential in drama.
The definition of a cretin is a very stupid person, or a person suffering from the disease cretinism, which causes mental problems and deformity. An example of a cretin is a person who constantly makes stupid and horrible mistakes. 2  An example of a cretin is someone with physical deformities due to the disease.
Definition of deletion. 1 : the act of deleting. 2a : something deletedb (1) : the absence of a section of genetic material from a gene or chromosome (2) : the mutational process that results in a deletion.