Posse is the infinitive of an irregular Latin verb meaning to be able. It can also be used as a noun meaning ability, power, potentiality. Two common phrases that use â¦ posse this way are a posse ad esse - from possibility to reality (literally .. . to being)posse comitatus - the power of the county.ctually that is an English word; the Latin form was originally benevolens..    bene = good   volens = wanting    So it means, wanting good.  Acually I a â¦ m a different person that improved this answer and benevolent is a Latin word. 5 people found this useful.