palæo

Paläo is a combining form derived from the Greek palaios meaning ancient or old. It is used in scientific and scholarly terms to denote something relating to the distant past or prehistoric times.

Examples include paleontology (the science of prehistoric life), palaeobotany (the study of fossil plants), palaeogeography (the historical geography of the Earth's surface), palaeoclimatology (the reconstruction of ancient climates), and palaeography (the study of ancient writing). The prefix also appears in names of geological periods and epochs, such as the Paleogene and Paleocene, and in German as Paläozän and Paläozoikum.

Variant spellings reflect language tradition: paleo- (American English), palaeo- (British English and many scientific terms), palæo- (older English typographic ligature), and Paläo- (German).

Note: paläo is not a standalone word but a combining form used to form compounds. It is commonly applied across disciplines such as paleontology, palaeography, palaeobotany, and paleoclimatology to describe ancient forms, events, or processes.