Preliminary
mid 17th century: from modern Latin praeliminaris or French préliminaire, from Latin prae ‘before’ + limen, limin- ‘threshold’.
wiktionary
From the French préliminaire or from Modern Latin praelīmināris, formed from prae-(“before”) + līmen(“threshold”) + -āris(adjectival suffix); compare Latin līmināris(“of or belonging to a threshold”).
etymonline
preliminary (adj.)
"preceding and leading up to something more important," 1660s, from French préliminaire and directly from Medieval Latin praeliminaris, from Latin prae "before" (see pre-) + limen (genitive liminis) "threshold" (see limit (n.)). A word that arose in reference to painstaking diplomatic negotiations to end the Thirty Years' War. Earliest attested form in English is preliminaries (n.) "things which lead up to or introduce following matter or events," 1650s.
