What does biassed mean?
Biassed means unfairly inclined toward or against a person, group, idea, or outcome — prejudiced rather than neutral. It appears most often in discussions of judgement, reporting, research, and decision-making: a biassed judge favours one side, a biassed survey question nudges respondents toward particular answers, and a biassed sample distorts statistical findings. The word implies systematic distortion rather than simple error or honest disagreement, which gives it real force when describing flawed evidence or partial treatment. Spelled with a double 's', it is a chiefly British variant of the now-standard 'biased'; even in the UK the single-s form has become dominant, so 'biassed' reads as slightly old-fashioned or formal today. The underlying noun, bias, traces back through French biais to a notion of oblique or slanting direction, which is exactly what the adjective preserves figuratively — a mind or method leaning off the straight line of impartiality.
Unfairly prejudiced for or against someone or something; showing an inclination that prevents impartial judgement.
"He admitted his long friendship with the candidate had left him biassed."
Now usually spelled 'biased'.
Past tense and past participle of 'bias' — to have influenced unfairly or given a slant to.
"The funding arrangement biassed the researchers' conclusions."
That extra 's' isn't a typo — it's a centuries-old British spelling habit that still shows up in formal UK legal writing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of biassed
Biassed derives from bias, a noun adopted into English from French biais in the mid-16th century, originally denoting a diagonal or oblique line — as in lawn bowls, where a 'biased' bowl curves off the direct path. The adjective arose in the 17th century by extension, describing anything that leans or slants away from neutrality. The double-s spelling reflects older British orthographic convention, but modern usage overwhelmingly prefers the single-s 'biased'. Cognate notions appear in the French biais itself, meaning slant or slope.
Related word forms
How biassed is actually used
The double-s spelling is now largely confined to British English and is increasingly replaced by 'biased' even there. In statistics and law, the word carries a connotation of systematic unfairness rather than mere opinion. Avoid using 'biassed' informally; 'biased' is safer in most modern contexts.
Easily confused with biassed
'Biassed' means prejudiced or slanted, while 'based' means founded or grounded on something.