alexo-, alex-, alexi-

Ancient Greek, a male name: The Dawsons gave their newborn son the name Alexander, which referred to Alexander the Great, known to be a great military leader.

A substance which is protective against infection or poison: Jack read about a certain antiseptic callee alexeteric, which belonged to the class biguanide.

A preservative against evil; a safeguard against bad: The hunter wore an alexikakon around his neck as a talisman to protect him from wild animal attacks.

An antibacterial substance: At the pharmacy, Mrs. Thompson asked for alexidine, which was used in contact lens disinfecting solutions.

A class of defensive substances found in blood-serum that destroys bacteria and other cells: In his class on biochemistry, Tom learned about alexin that existed in any bodily fluid and was able to kill microorganisms.

Outdated, a remedy for warding off the ill effects of a poison: Alexipharmac is especially good as an antidote against a poisonous snake bite.

Outdated, referring to a substance that protects against or fends off the bad effects of a harmful matter: Susan suggested that they take an alexipharmacal remedy with them on their weekend trip to the desert, just in case they get bitten by a poisonous snake.

Historical, outdated, an antidote: An alexipharmic was used to expel or counteracting poison.

An alexipharmic was especially good in protecting the body from the venom of a snake.

Outdated, a substance that reduces fever; antipyretic: Sally's mother gave her an alexipyretic because her daughter had come down with a bad flu and had a high temperature.

A name given to a male person: The parents called their little boy Alexis that originated from Ancient Greek and came into use in the 1940s.

In medicine, regarding a substance that resists poison or venom: An alexiteric substance can be used as a preventive against infectious or contagious illnesses.

Outdated, an antidote to poison: In his father's old medical book, Jack read about alexiteries that were used in former times to counteract all kinds of toxic substances.

A leucocyte that presumably provide alexins: In her medical book, Jenny read that alexocytes were probably responsible for supplying those substances found in blood-serum that kills bacteria and other cells.

Any substance that is produced by plant tissues in response to contact with a parasite and specifically inhibits the growth of that parasite.

The term phytoalexin was originally defined with regard to fungal parasites only, but in 1956 it was extended to cover all parasites [According to the Oxford English Dictionary].