There are multiple definitions - click on the translation that matches your context.

desertar

verbo

partial

desert

verb

Definitions of desert

English

to abandon (=to leave forever) a person, cause, or organization in a way considered disloyal (=not supporting someone or something when you should)

He arrived here a month ago after deserting his wife and four children.

English

to leave the armed forces illegally with no intention of returning

An Iraq veteran who deserted the US army saying the war was illegal is seeking asylum in Germany.