LATIN DICTIONARYLexicon Latīnum
suffixthird conjugation

-essō

-essō (present infinitive -essere, perfect active -essīvī or -essiī or -essī, supine -essītum)
Classical[ˈɛs.soː]Ecclesiastical[ˈɛs.so]

Meaning

  1. morphemeForms a small number of intensive verbs from verbs.
    petessō (“to strive eagerly”), from the verb petō (“to aim, seek”).
    facessō (“to do eagerly; to depart”), from the verb faciō (“to do, make”)

Origins

Identical in form to the archaic future perfects in -āssō, -āssere, etc., attested contemporary with Ennius, viz. amāssis, levāssō, impetrāssere, and iūdicāssit, respectively of amō, levō, impetrō, and iūdicō. Origin cited as not fully explained. Perhaps connected with a kind of prolepsis invoking a counterfactual use of aspect for emphasis.

Quick answers

What does -essō mean in Latin?
-essō, a suffix, means “Forms a small number of intensive verbs from verbs.”.
How do you pronounce -essō?
In classical Latin, [ˈɛs.soː]; in ecclesiastical (church) Latin, [ˈɛs.so].