adj, noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A pesticide or herbicide that has relatively low toxicity and causes relatively little damage to the environment.

Adjective

1. 1
   Of a pesticide or herbicide: having relatively low toxicity, and causing relatively little damage to the environment. not-comparable

Etymology

From bio- + rational.

Data sourced from Wiktionary, WordNet, CMU, and other open linguistic databases. Updated March 2026.