Where does “secessionalist” come from?

secessionalist (English) comes from English secessional, from English secession, from Latin sēcessiō, from Latin -tiō, from Latin dissertātiō, from Latin dissertus, from Latin disserere, from Latin dis- — small stone, pebble; gravel, rubble.

Ancestry of “secessionalist”, step by step

secessionalist traces back through two separate lines of ancestry.

via English secessional

StepLanguageWordMeaning
1EnglishsecessionalRelating to secession
2EnglishsecessionThe act of seceding
3LatinsēcessiōA going aside, withdrawal, retirement
4Latin-tiōtion, -ation, -ing
5Latindissertātiō(spoken) dissertation, discourse, disquisition
6Latindissertusarranged, disposed; explained
7Latindissereresecond-person singular future passive indicative...
8Latindis-asunder, apart, in two; reversal, removal;...
9Latincalceusshoe
10Latincalxlimestone; chalk; the finish line
11Ancient Greekχάλιξsmall stone, pebble; gravel, rubble

via English ist

StepLanguageWordMeaning
1EnglishistA practitioner or supporter of an ism
2English-istAdded to words to form nouns denoting
3Old French-iste
4Latin-ista-ist; one who practises or believes
5Ancient Greek-ιστήςAlternative form of -τής; -ist
6Ancient Greek-τήςAppended to verbs to form agent nouns
7Proto-Hellenic-tās
Every word from Ancient Greek χάλιξEvery word from Latin -tiōEvery word from Latin dis-