Bio-Informer Biology Dictionary
A respectfully sized collation of biological terms all to be found on the one page.
http://www.angelfire.com/nv/biology/dictionary.html

Biotech's Life Science Dictionary
Contains terms associated with genetics, biochemistry, biotechnology, botany, chemistry, ecology, pharmacology, toxicology and medicine. Searchable by term or definition.
http://biotech.icmb.utexas.edu/search/dict-search.html

Glossarist.com - Life Science Glossaries > Biology
An organised collection of biology glossaries available on the web today as part of a wider more generic collection.
http://www.glossarist.com/glossaries/science/life-sciences/biology.asp

Dictionary of Cell Biology
Intended to provide quick access to easily-understood and cross-referenced definitions of terms. Features a graphical interface. Full access requires registration.
http://on.to/cellbiology

OneLook Dictionary
Free search access to a frequently updated database of words, terms, names, and acronyms.
http://onelook.com/