hept, sept

seven

Spelled hept, sept · hepta 'seven' (sept- forms are from Latin septem 'seven')

Greek hepta and Latin septem mean seven: a heptagon has seven angles, a septet seven performers, and a septennial returns after seven years.

Words built from it

heptagon — a shape with seven sides
hept (seven) + -agon (angle, from Greek gonia)
septet — a group of seven musicians or things
sept (seven) + -et (small group)
heptathlon — an athletic contest with seven events
hept (seven) + athlon (contest)
septuple — sevenfold, or to multiply by seven
sept (seven) + -uple (times, fold)
septennial — occurring every seven years
sept (seven) + -ennial (yearly, from annus)
septuagenarian — a person in their seventies
sept (seven) → Latin septuaginta (seventy) → septuagenarius (seventy years old)

septic — From Greek sepein 'to rot, decay' (root of sepsis); refers to infection and rot, unrelated to Latin septem 'seven'.