'astrognosy' originates from Greek, specifically the elements 'astron' and 'gnosis', where 'astron' meant 'star' and 'gnosis' meant 'knowledge'.

'astrognosy' is a Modern English formation combining the Greek roots 'astron' + 'gnosis'; it appears as a learned or archaic term in English usage from roughly the 17th–19th centuries to denote knowledge of the heavens.

Initially, it meant 'knowledge of the stars', and over time this core meaning has largely remained the same though the term became rare/archaic compared with 'astronomy'.