The term marriage lite is a compound form inspired by commercial products such as Coca-Cola Lite, a modified cola drink which contains less sugar than standard Coca-Cola. The adjective lite dates from the mid-20th century as a variant spelling of light (‘not weighing much’), and can be used productively to mean ‘containing a low amount of something’, usually sugar, alcohol or fat as in, e.g. lite beer or lite mayonnaise. In the term marriage lite, the analogy is presumably of a union between two people which does not contain all of the ingredients of a standard marriage.