Here is the collection of online dictionary links.

Dictionary.com
Dictionary.com provides a searchable online dictionary and contains links to other online dictionaries.

Encyberpedia
Website contains links to numerous dictionary, glossary and encyclopedia resources.

Infoplease
Infoplease provides historical facts, atlas, encyclopedia, dictionary, thesaurus and more.

Lexico
An online dictionary powered by the Oxford Dictionaries.

Merriam-Webster
Merriam-Webster's searchable online dictionary

Netdictionary
Netdictionary is an alphabetical reference guide to technical, cultural, and humorous terms related to the Internet.

NetLingo
This online dictionary contains definitions of hundreds of words that are emerging as a new vocabulary surrounding the technology and community of the Internet and the World Wide Web.

OneLook Dictionaries
A searchable collection of online dictionaries. Contains over 2 million words from over 400 dictionaries.

Open Directory: Dictionary Links
The Open Directory's collection of links to hundreds of online dictionaries.

Oxford English Dictionary (OED)
The online service of the Oxford English Dictionary with information about over 600,000 words.

Roget's Thesaurus
Searchable online version of Roget's Thesaurus.

Semantic Rhyming Dictionary
An online rhyming dictionary. Useful for help writing poetry, song lyrics, greeting cards, witticisms, etc.

Theodora's Culinary Dictionary
A glossary of food industry terminology.

Webopaedia
Definitions of new terms to keep pace with the constantly expanding language of technology.

Words in the News
Coverage of Word of the Day features and hot words from Writers Write

WorldWideWeb Acronym and Abbreviation Server
Database which allows you to search the list of acronyms and abbreviations in the Network Acronym and Abbreviation Server

Yahoo Reference: Dictionaries
Yahoo's collection of online dictionary links.