Bt

1 of 2

noun

ˈbē-ˈtē 

: a preparation of a bacterium (Bacillus thuringiensis) often modified by genetic engineering for use as a biopesticide against insects and especially lepidopteran larvae

also : the bacterium itself

Bt

2 of 2

abbreviation

baronet

Examples of Bt in a Sentence

Recent Examples on the Web

Noun

Finally, use a spray of Neem oil or an organic insecticide that contains Bacillus thuringiensis, a bacterial disease that only affects caterpillars and is commonly referred to as Bt. — Mary Marlowe Leverette, Southern Living, 14 Aug. 2025

These include many species of birds, mammals, amphibians and reptiles, as well as predatory insects and spiders, and pathogens specific to pests, such as Bt (Bacillus thuringiensis) for many caterpillars. — Nanette Londeree, Mercury News, 4 Aug. 2025

For heavy infestations, use an insecticide containing Bt (Bacillus thuringiensis var. — Lauren Landers, Better Homes & Gardens, 25 June 2025

Mosquito Bits contain the biological pesticide Bt, which kills worms, caterpillars (so be careful with it around pollinator plants) and mosquito larvae. — Nan Sterman, San Diego Union-Tribune, 5 Apr. 2025

Use Organic Insecticides Bt, insecticidal soap, and neem oil are derived from natural materials and can be used on specific pests. — Leanne Potts, Better Homes & Gardens, 3 Apr. 2025

The way the toxin gains entry is by activation of Bt’s chitinase which degrades the chitin lining a larva’s digestive tract. — Joshua Siskin, Orange County Register, 8 Mar. 2025

Word History

Etymology

Noun

New Latin Bacillus thuringiensis, species name, literally, Thuringian bacillus

First Known Use

Noun

1971, in the meaning defined above

Medical Definition

BT

abbreviation

1

bedtime

2

brain tumor