biotoxin (BI-oh-tahk-sihn)
noun.

poisonous substance produced by a living organism.

designer toxin (dee-ZI-nur TAHK-sihn)
noun.

poison manufactured to destroy harmful pests or diseases.

neurotoxin (NOO-roh-tahk-sihn)
noun.

substance that interferes with the functioning of nerves or the nervous system.

toxin (TAHK-sihn)
noun.

poisonous substance, usually one produced by a living organism.