/ˌpɑːrʃiˈælɪti/
[noun] A tendency to favour one person, group, or thing over another in a way that is not fair; also, a special liking or fondness for something.
This word carries two completely opposite feelings — unfair bias and innocent personal fondness — hidden inside the same spelling.
The story of 'partiality' begins with the Latin word 'pars', meaning 'a part' or 'a portion'. This humble root — the idea of something being divided, of one piece being separated from a whole — turns out to be extraordinarily generative in the history of language. From 'pars' came the adjective 'partialis', a Late Latin word meaning 'relating to a part' or 'incomplete', as opposed to something whole and total. It was this sense of being only a portion of something larger that quietly planted the seeds of the word's later meanings.
From Latin 'partialis', the word moved into Old French as 'parcial' and then 'partial', carrying with it the notion of being one-sided — of looking at only part of the picture rather than the whole. Medieval thinkers used this idea in both logical and moral contexts. A judge who favoured one side was seeing only 'part' of the truth; a person who loved strawberries above all other fruits had given only 'part' of their affection to the full range of things available. The word entered Middle English in the 14th century as 'partial', and the abstract noun 'partiality' followed naturally in the 15th century, built on the pattern of forming nouns with the suffix '-ity', which itself descended from the Latin '-itas'.
What makes 'partiality' so linguistically interesting is that it developed two quite distinct meanings that sit side by side without resolving into one another. On one hand, partiality is a serious failing — a bias, a corruption of fair judgement. A judge who shows partiality in a courtroom is behaving unethically, allowing personal feelings to corrupt what should be an impartial process. On the other hand, 'a partiality for chocolate cake' or 'a partiality for long walks' is perfectly harmless — it simply means a personal preference, a fondness. Both senses come from the same root idea of leaning toward one part over another, but one is morally charged and one is cheerfully neutral.
The negative sense — partiality as unfairness — was the earlier and more dominant meaning in English for centuries. Courts, churches, and parliaments all worried about partial judges and partial referees, people whose loyalties to one faction made them unable to decide fairly. The word 'impartial', meaning free from such bias, appeared in the late 16th century as its direct antonym, built by adding the Latin prefix 'im-' (meaning 'not'). Latin 'pars' → Late Latin 'partialis' → Middle English 'partial' → English 'impartial' — the chain of meaning runs in a clear line, and 'impartiality' remains the standard term in legal and journalistic language today.
The gentler sense of 'partiality' as innocent fondness seems to have grown more common in the 17th and 18th centuries, as English writers began using it in personal letters and literature to describe soft preferences and quiet pleasures. Jane Austen, for example, was perfectly comfortable writing about a character's 'partiality' toward another person as a near-synonym for romantic inclination or deep liking. This gave the word a warmer, more human texture alongside its colder legal one. The Latin root 'pars' also fed, through different routes, into 'party' (Old French 'partie' → English 'party'), 'partner', 'apartment' (Italian 'appartamento'), and 'parse' — a remarkable family tree from one small Latin word meaning simply 'a piece'.