ἀκοινονόητος → lacking in common sense, with no regard for others

[spiros]

ἀκοινονόητος → lacking in common sense

LSJ has:
lacking in savoir-faire (Lat. sensus communis)

Is savoir-faire (know-how?) appropriate here?

[billberg23]

LSJ is unusually misleading when they cite French savoir-faire ("know-how") in reference to this word or to Latin sensus communis.  Αmong Greek authors, only Marcus Aurelius 1.16.2.2 uses a related word, κοινονόημα, meaning "sensitivity to feelings of others"; ἀκοινονόητος is not present in any authentic Greek author. Τhe Latin authors who use it (or configure it) all mean "insensitive," "intolerant," "unfeeling," literally "lacking in fellow-feeling," in keeping with their own sensus communis, "fellow-feeling," i.e. humane attitude.

[spiros]

Popular enough to be included in Latin dictionaries: ἀκοινονόητος → acoenonoetus, communi carens sensu; and DGE (ἀκοινονόητος - Ancient Greek (LSJ), que carece de sentido común [lacking common sense]).
Maybe there is also confusion with ἀκοινώνητος - Ancient Greek (LSJ)

[billberg23]

An added complication is the fact that Latin communis sensus is (lexically speaking) a "false friend," in that it often slips into modern languages as "common sense," i.e. "(plain) clear thinking," whereas the Latin meaning is rather a "(commonly) shared feeling."

[spiros]

The everyday understanding of common sense derives from historical philosophical discussion involving several European languages. Related terms in other languages include Latin sensus communis, Greek κοινὴ αἴσθησις (aísthēsis koinḕ), and French bon sens, but these are not straightforward translations in all contexts. Similarly in English, there are different shades of meaning, implying more or less education and wisdom: "good sense" is sometimes seen as equivalent to "common sense", and sometimes not.
Common sense - Wikipedia

sensus communis
Not common sense in its ordinary meaning, but in Aristotle (De Anima, II, 1–2) and following him Aquinas and others, a central cognitive function that integrates and monitors the delivery of the other distinct senses, as when a shape is both seen and felt
Sensus communis - Oxford Reference

sensus communis
in the thought of Aristotle, the mental faculty that takes data provided by the five senses and integrates them into unified perceptions. The operations of the sensus communis (Latin, “common sense”) were thought to occur in the sensorium commune.
APA Dictionary of Psychology

[billberg23]

Apart from modern analyses and interpretations, the Oxford Latin Dictionary, s.v. communis #5, defines sensus communis as "feeling for others in the same community (as a guide to conduct, etc.)."  Cf. e.g. Juvenal 8.73f. rarus enim ferme sensus communis in illa fortuna → "for in those high places regard for others is rarely to be found" (Loeb trans.).