Prefix · position · around
Means "around" or "near": perimeter, peripheral, periscope, period, peril, perennial.
Written by Bryan López, English teacher · Updated
Peri- comes from Greek "peri" (around, near, about) and signals that something surrounds, encloses, or is close to something else: perimeter = measure around a shape; peripheral = at the edges around the centre; periscope = an instrument for seeing around obstacles; pericardium = the membrane around the heart; perihelion = the point in an orbit nearest to (around the closest to) the sun.
Peri- is especially productive in scientific and medical vocabulary: perihelion (astronomy, nearest point to the sun), pericardium (medicine, sac around the heart), perinatal (medicine, around the time of birth), peristalsis (physiology, wave-like contraction around the digestive tube), peripheral nervous system (the nerves around and outside the central nervous system).
Attaches to Greek and Latin roots to signal surrounding or nearness:
Pronunciation: /ˈperɪ/. Do not confuse with circum- (Latin, also "around"): perimeter is Greek, circumference is Latin. Both mean "around" but come from different traditions and are not interchangeable.
peri-/ˈperɪ/
Tap the button to hear how the prefix sounds. Each word in the table has its own audio.
English inherited two "around" prefixes from different traditions: peri- (Greek) in perimeter, periscope, peripheral; and circum- (Latin) in circumference, circumnavigate, circumscribe. The word's historical root determines which prefix it takes. "Periference" and "circumscope" do not exist.
A trick to remember it
Peri- = around. Spanish cognates: perimeter/perímetro, peripheral/periférico, period/período, periodic/periódico. It is especially common in scientific and medical vocabulary — learn it once and unlock a large technical vocabulary.
Exercise 1 · Form the word
Exercise 2 · Pick the right one
What does "peripheral" mean in the context of vision?
The prefix peri- means "around" or "near": perimeter, peripheral, periscope, period, peril, perennial. In Spanish it usually maps to peri-.
The prefix peri- is pronounced /ˈperɪ/. For example, "perimeter".
"meter" becomes "perimeter". It is a typical example of the peri- prefix.
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