any malignant growth or tumor caused by abnormal and uncontrolled cell division; it may spread to other parts of the body through the lymphatic system or the blood stream
"The doctor explained that if the cancer spreads to other organs through the bloodstream, the treatment plan will need to change immediately."
a small zodiacal constellation in the northern hemisphere; between Leo and Gemini
"When I looked up at the night sky, I spotted Cancer nestled perfectly between the stars of Leo and Gemini."
the fourth sign of the zodiac; the sun is in this sign from about June 21 to July 22
"As a Cancer, I was born right after the summer solstice."
type genus of the family Cancridae
"The deep-sea researcher spent hours cataloging new species within the Cancer genus to update the taxonomic records for the Cancridae family."
A disease in which the cells of a tissue undergo uncontrolled (and often rapid) proliferation.
"She was born under Cancer, so she tends to be very protective of her family and emotions."
Someone with a Cancer star sign.
In plain English: Cancer is a serious illness where cells grow out of control and form tumors that can spread to other parts of the body.
"The doctor told me that my grandfather had cancer."
Usage: Cancer refers to a malignant disease affecting living organisms, not a person born under a specific astrological sign. Using it to describe someone's zodiac birth date is incorrect and should be avoided in formal or general communication.
A constellation of the zodiac supposedly shaped like a crab.
"The ancient astrologer insisted that the sign known as Cancer represents a giant crab in the sky."
The English word "cancer" was borrowed from Latin, where it originally meant "crab." It was applied to human tumors because doctors noticed that the swollen veins around them looked like the legs of a crab.