A more thorough explanation:

Definition: Criminal desertion refers to the willful and unjustified abandonment of a person's duties or obligations, especially to military service or to a spouse or family. It is also known as gross neglect of duty. In family law, spousal desertion involves five elements: cessation of cohabitation, lapse of a statutory period, intention to abandon, lack of consent from the abandoned spouse, and lack of spousal misconduct that might justify the abandonment.

Examples:

• One spouse leaves the marital home without any justifiable reason and fails to provide for the care, protection, or support of the other spouse who is in ill health or needy circumstances. This is an example of criminal desertion.
• A soldier who abandons his or her military duties without any valid reason is guilty of criminal desertion.

The examples illustrate that criminal desertion involves a willful and unjustified abandonment of one's duties or obligations, which can have serious consequences for the affected parties. In the case of spousal desertion, it can lead to the breakdown of the marriage and legal action such as divorce. In the case of military desertion, it can result in disciplinary action and criminal charges.