'pseudoscientific' originates from modern English compounds, specifically the prefix 'pseudo-' (from Greek 'pseudes') meaning 'false' and the adjective 'scientific' (from Latin 'scientificus', ultimately from 'scire' meaning 'to know').

'pseudoscientific' developed as a compound of 'pseudo-' + 'scientific' (earlier written as 'pseudo-scientific'); the parts derive from Greek and Latin roots and the compound form became established in English in the late 19th to early 20th century.

Initially it meant 'false or pretended science'; over time it has come to denote claims, practices, or theories that present themselves as scientific but lack methodological rigor or supporting evidence.