Firefox add-on with keyword - definition
Add-ons (also known as extensions) are small programs that run inside web browsers like Mozilla Firefox. They add extra features to the browser without having to download anything new. You can use extensions to make browsing faster, easier, and safer. Some extensions even let you do things like translate text on websites, search the web, and play games.
There are over 28,000 Firefox-addons and 480,000 themes, making it hard to find the best ones. so we have created a way to sort through all of them. Use the dropdown above to set different filters. Add-ons are sorted by number of active users.
To set even more advanced filters, and sort the Firefox add-ons differently, please visit our Advanced search tool. Note that Advanced search tool is only available to premium members.
![YouTube High Definition](https://addons.mozilla.org/user-media/addon_icons/328/328839-64.png?modified=mcrushed)
#1, YouTube High Definition
![YouTube High Definition](https://addons.mozilla.org/user-media/addon_icons/328/328839-64.png?modified=mcrushed)
![Dictionary Anywhere](https://addons.mozilla.org/user-media/addon_icons/970/970075-64.png?modified=75108a94)
#2, Dictionary Anywhere
![Dictionary Anywhere](https://addons.mozilla.org/user-media/addon_icons/970/970075-64.png?modified=75108a94)
![Definitions.net](https://addons.mozilla.org/user-media/addon_icons/934/934878-64.png?modified=1553684824)
#3, Definitions.net
![Definitions.net](https://addons.mozilla.org/user-media/addon_icons/934/934878-64.png?modified=1553684824)
![English Dictionary Anywhere - Definition PopUp](https://addons.mozilla.org/user-media/addon_icons/2672/2672668-64.png?modified=1e1ba7f1)
#4, English Dictionary Anywhere - Definition PopUp
![English Dictionary Anywhere - Definition PopUp](https://addons.mozilla.org/user-media/addon_icons/2672/2672668-64.png?modified=1e1ba7f1)
![Video DownloadHelper](https://addons.mozilla.org/user-media/addon_icons/3/3006-64.png?modified=101feb6e)
#5, Video DownloadHelper
![Video DownloadHelper](https://addons.mozilla.org/user-media/addon_icons/3/3006-64.png?modified=101feb6e)
![YouTube Anti Adblock Definitive Fix](https://addons.mozilla.org/user-media/addon_icons/2824/2824193-64.png?modified=25463a2f)
#6, YouTube Anti Adblock Definitive Fix
![YouTube Anti Adblock Definitive Fix](https://addons.mozilla.org/user-media/addon_icons/2824/2824193-64.png?modified=25463a2f)
![Definer - Popup Dictionary & Translator](https://addons.mozilla.org/user-media/addon_icons/2707/2707951-64.png?modified=8cd545e1)
#7, Definer - Popup Dictionary & Translator
![Definer - Popup Dictionary & Translator](https://addons.mozilla.org/user-media/addon_icons/2707/2707951-64.png?modified=8cd545e1)
![PopUpOFF](https://addons.mozilla.org/user-media/addon_icons/2646/2646176-64.png?modified=a435ab54)
#8, PopUpOFF
![PopUpOFF](https://addons.mozilla.org/user-media/addon_icons/2646/2646176-64.png?modified=a435ab54)
![Laban dictionary](https://addons.mozilla.org/user-media/addon_icons/753/753194-64.png?modified=1510806022)
#9, Laban dictionary
![Laban dictionary](https://addons.mozilla.org/user-media/addon_icons/753/753194-64.png?modified=1510806022)
![Power Thesaurus - Synonyms & Antonyms](https://addons.mozilla.org/user-media/addon_icons/697/697681-64.png?modified=90292ce8)
#10, Power Thesaurus - Synonyms & Antonyms
![Power Thesaurus - Synonyms & Antonyms](https://addons.mozilla.org/user-media/addon_icons/697/697681-64.png?modified=90292ce8)
![Cnrtl](https://addons.mozilla.org/user-media/addon_icons/945/945884-64.png?modified=c9988c4e)
#11, Cnrtl
![Cnrtl](https://addons.mozilla.org/user-media/addon_icons/945/945884-64.png?modified=c9988c4e)
![Ogame Infinity (Dark Edition)](https://addons.mozilla.org/user-media/addon_icons/2749/2749157-64.png?modified=fb43f949)
#12, Ogame Infinity (Dark Edition)
![Ogame Infinity (Dark Edition)](https://addons.mozilla.org/user-media/addon_icons/2749/2749157-64.png?modified=fb43f949)
![Perapera Chinese Popup Dictionary](https://addons.mozilla.org/user-media/addon_icons/899/899379-64.png?modified=1648138451)
#13, Perapera Chinese Popup Dictionary
![Perapera Chinese Popup Dictionary](https://addons.mozilla.org/user-media/addon_icons/899/899379-64.png?modified=1648138451)
![Reload PAC button](https://addons.mozilla.org/user-media/addon_icons/540/540954-64.png?modified=1525962023)
#14, Reload PAC button
![Reload PAC button](https://addons.mozilla.org/user-media/addon_icons/540/540954-64.png?modified=1525962023)
![Cambridge English Dictionary](https://addons.mozilla.org/user-media/addon_icons/2649/2649007-64.png?modified=7f95b0fc)
#15, Cambridge English Dictionary
![Cambridge English Dictionary](https://addons.mozilla.org/user-media/addon_icons/2649/2649007-64.png?modified=7f95b0fc)
#16, Black Rock Shooter - BRS - Definitive
#17, swag definition
![Auto HD/4k/8k for YouTube™](https://addons.mozilla.org/user-media/addon_icons/1014/1014962-64.png?modified=78ee5daa)
#18, Auto HD/4k/8k for YouTube™
![Auto HD/4k/8k for YouTube™](https://addons.mozilla.org/user-media/addon_icons/1014/1014962-64.png?modified=78ee5daa)
![Zoom Page WE](https://addons.mozilla.org/user-media/addon_icons/725/725990-64.png?modified=1b04a853)
#19, Zoom Page WE
![Zoom Page WE](https://addons.mozilla.org/user-media/addon_icons/725/725990-64.png?modified=1b04a853)
#20, Definition Of Perfect
![Context Wiktionary](https://addons.mozilla.org/user-media/addon_icons/693/693434-64.png?modified=1458757217)
#21, Context Wiktionary
![Context Wiktionary](https://addons.mozilla.org/user-media/addon_icons/693/693434-64.png?modified=1458757217)
![toktogi](https://addons.mozilla.org/user-media/addon_icons/501/501800-64.png?modified=1512883222)
#22, toktogi
![toktogi](https://addons.mozilla.org/user-media/addon_icons/501/501800-64.png?modified=1512883222)
![_rozi Wiktionary and Google Translate](https://addons.mozilla.org/user-media/addon_icons/1008/1008412-64.png?modified=ffa8f70c)
#23, _rozi Wiktionary and Google Translate
![_rozi Wiktionary and Google Translate](https://addons.mozilla.org/user-media/addon_icons/1008/1008412-64.png?modified=ffa8f70c)
#24, The Real Definition of MSCRE
![Sourcegraph for Firefox](https://addons.mozilla.org/user-media/addon_icons/1010/1010429-64.png?modified=d179f29e)
#25, Sourcegraph for Firefox
![Sourcegraph for Firefox](https://addons.mozilla.org/user-media/addon_icons/1010/1010429-64.png?modified=d179f29e)