Entomology definition of Trigonulum September 14, 2014 Raj Entomology Dictionary 0 Please Like Us!!! DesiGoogly.com > Education News > Entomology Dictionary > Entomology definition of Trigonulum Entomology definition of Trigonulum: in Odonata, = triangle. Entomology Trigonulum definitionTrigonulum Entomology explanationTrigonulum Entomology meaningReviews & Comments