Inspired by this tweet, I opened the LSJ 1912 and got distracted.
ἰδιάζω: “to live as a private person”
ἰδιασμός: “peculiarity”
ἰδιόβιος: “living by or for oneself”
ἰδιόγλωσσος: “of distinct, peculiar tongue”
ἰδιογνώμων: “private opinion”
ἰδιοθανέω: “to die in a peculiar way”
ἰδιολογία: “private conversation”
ἰδιοξενία: “private friendship”
ἰδιοπάθεια: “feeling for oneself alone”
ἰδιοποιέω: “to make separately” in the middle: “to appropriate to oneself”
ἰδιόσημος: “peculiar in signification”
ἰδιόστολος: “equipt at private expense”
ἰδιοσύγκριτος: “Peculiarly composed”
ἰδιόφωνος: “with one’s own voice”
ἰδιοφυής: “of peculiar nature”
ἰδιόχειρος: “written by one’s own hand”
ἰδίωμα: “a peculiarity”
ἰδιωματικός: “characteristic”
ἰδίωσις: “distinction between things”
ἰδιωτεία: “private life or business”
ἰδιωτεύω: “to be a private person”
ἰδιώτης: “a private person, an individual” 2cL “unpracticed, unskilled, ignoant, ill-informed”
ἰδιωτίζω, “to put into a common language”
ἰδιωτικός: “of or for a private person”; 2: “unprofessional, rude”
ἰδιώτις: “inconsiderable”
ἰδιωτισμός: “the way or fashion of a common person”
ἰδιωφελής: “privately profitable”
‘idio-‘ retains its non-pejorative meaning in English ‘idiosyncracy’.
Yes it does. Also, idiopathic!