Origins
The word 'opportunity' contains one of the most elegant buried metaphors in the English language. Latin 'opportūnus' (favorable, fit, timely) was originally a nautical term, composed of 'ob-' (toward, assimilated to 'op-' before 'p') + 'portus' (harbor). An 'opportune' wind was one that blew toward the harbor — a favorable wind that carried sailors safely home. The noun 'opportūnitās' abstracted this nautical image into the general concept of a favorable moment.
The connection to the 'portāre' (to carry) family is indirect but genuine. Latin 'portus' (harbor) and 'portāre' (to carry) both derive from PIE *per- (to lead, pass over, carry across). A 'portus' was a place of passage — where goods and people were carried across from sea to land. 'Opportunity' thus belongs to the deep Indo-European family of words about crossing, carrying, and passage, even though its immediate ancestor is 'portus' rather than 'portāre.'
The word entered English through Old French 'opportunité' in the late fourteenth century. Its earliest English uses already carried the abstract sense of a favorable moment for action, but the nautical metaphor was still alive in speakers' minds. The image of a favorable wind — one that comes and goes, that must be seized when it arrives — captures the essential quality of opportunity: its temporariness. A wind that blows toward harbor will not blow forever; a favorable moment for action will not last.
Development
The derivative 'opportunism' (acting according to what is immediately advantageous rather than to principles) appeared in the nineteenth century, originally in French political discourse. An 'opportunist' was a politician who shifted positions to catch whatever favorable wind was blowing — a pejorative use that inverts the positive connotation of 'opportunity' itself. The word carries a moral charge: opportunity is good, but being too eager to exploit every passing opportunity reveals a lack of principle.
The phrase 'equal opportunity' became a cornerstone of civil rights and employment law in the twentieth century. The concept — that all people should have the same favorable winds available to them — gave the ancient nautical metaphor profound political significance. 'Equal opportunity employer,' 'opportunity gap,' 'opportunity cost' — the word has become central to both economic theory and social justice discourse.
NASA named its Mars rover 'Opportunity' (launched 2003), which explored the Martian surface for over fourteen years — far exceeding its planned 90-day mission. The rover's name invoked the original Latin metaphor: the wind of scientific possibility blowing toward the harbor of knowledge. Opportunity's final transmission, before a global dust storm ended its mission in 2018, prompted widespread mourning — a sign of the power of a well-chosen Latin name.