Physiology, Biology, Plant Pathology, Plant Diseases, Soils, Physical Geography, Useful terminology

Bryological Glossary - in English

Bryological Glossary - in Spanish

BugGuide - Iowa State University Entomology 

Convert Auto - Convert Just About Anything Automatically - Developed by Lilly Hammond

Curtis's Botanical Magazine

Encyclopedia of Earth  - a free, fully searchable collection of articles written by scholars, professionals, educators, and experts  

Flower structures and terminology from Palomar College

Glossary of Agroforestry - Easy to use terminologies - The Bugwood Network

Glossary of Biochemistry and Molecular Biology - by David M. Glick

Glossary of Chemistry - from the University of North Carolina

Glossary of Entomology - Entomology Purdue University

Glossary of Soil Science Terms - Soil Science Society of America

Glossary of Technical Terms in Plant Pathology - Phil Arneson - Cornell University

Jardine's Dictionary of Entomology - From BugGuide.net

Merriam-Webster Dictionary

Plant Anatomy Glossary - Glossary and slides - by Alison Roberts - URI

Plant Glossary - from MSU

Plant Biology Index - Developed and maintained by Wattana Pattanagul.

Plant Physiology Online - A companion to Plant Physiology Third Edition by Lincoln Taiz and Eduardo Zeiger

Scale net - Database of Scale insects from USDA

Schlumberger Oilfield Glossary - many easy to find useful terms and definitions

Site for short (150 words) multilingual translation - SYSTRAN Information and Translation Technologies

The NOAA weather calculator

UCMP Berkeley Glossary  - multi-media virtual glossary of biological terms

Visual Flower Glossary

Wiktionary - The free dictionary

WikipediA - The free Encyclopedia

Wildflower Glossary

Word Reference - Online English, French, Italian, Portuguese and Spanish word dictionary