The story
From socio- (prefix meaning ‘society’) + -petal (suffix meaning ‘travelling towards’), coined by the English psychiatrist Humphry Osmond (1917–2004) in 1957: see the quotation.
First known use, by meaning
- from 1957 Of a place, etc.: involving the arrangement of a group of people so that each person can see and interact with the others.
Etymology from Wiktionary, CC BY-SA 4.0.