Baretti: A dictionary of the English and Italian languages
Sedére, v. n. (siedo, siedi, siede, sediamo, sedete, siedono & sedono, &c. (poet.) seggo, seggono,from seggere, imperf. sedeva or sedea,)
1. to sit down, to seat one's self. Sedete, sit down. Ponetevi a —, be seated. Porsi a —, to rest, repose one's self. — a mensa, to sit at table;2. to lie, be situated on, placed. Siede Londra sopra il Tamigi, London is situated on the Thames. — pro tribunali, to sit in judgment, to hold a court of justice. — a scranna, to judge. Or tu chi sei, che vuoi — a scranna?who are you that pretend to judge? 3. to reign (speaking of the pope). Fu eletto e sedette Papa, mesi cinque, he was chosen Pope and reigned five months; 4. to be a judge, to be in the magistracy, to govern. Chi ben siede, mal pensa, idleness is the mother of vice.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
sedere: or síso, to sit or sit downe. Also to seat or situate. Also a seat or sitting place. Also a mans bum or arse. But properly all that part of the bodse whereon he sitteth.