per

through, thoroughly

Spelled per · per 'through, thoroughly'

Latin per carries movement through: drills perforate walls, smells permeate rooms, and a mood can pervade an entire gathering.

Words built from it

perfunctory — done as a routine duty, with little care or interest
per- (through) + funct (perform) + -ory (relating to)
permeate — to spread through every part of something
per- (through) + me (go) + -ate (verb ending)
perforate — to make a hole or holes through something
per- (through) + for (bore) + -ate (verb ending)
perennial — lasting for years or returning repeatedly
per- (through) + enn (year) + -ial (relating to)
pervade — to spread throughout a place or thing
per- (through) + vade (go)
persist — to continue despite difficulty or opposition
per- (thoroughly) + sist (stand firm)
perfect — complete and without faults
per- (thoroughly) + fect (make)

perilous — Built from peril, from Latin periculum 'danger'; its initial per is not this prefix.