'undogmatic' originates from English, specifically formed from the adjective 'dogmatic' with the prefix 'un-' where 'un-' meant 'not' and 'dogmatic' ultimately derives from Greek 'dogma' meaning 'opinion, decree'.

'undogmatic' was created in Modern English by adding the negative prefix 'un-' to 'dogmatic' (which came into English via Latin 'dogmaticus' and Greek 'dogmatikos' from 'dogma'), producing the literal sense 'not dogmatic'.

Initially, 'dogmatic' related simply to 'of or relating to dogma/opinions'; over time it gained the additional sense of 'asserting opinions in a rigid or uncompromising way', and 'undogmatic' came to mean 'not rigidly opinionated; open to other views'.