www.tolueislam.com/Parwez/expo/expo_glossary.htm (Arabic-English)
www.emuslim.com/quran/lughat.asp (English, Urdu, Bengali)
Classical Arabic lexicons/dictionaries (Arabic only)
www.muhaddith.org/lexicons.html (Arabic & English)
Lisan al-Arab, Taj al-Arus, Qamus al-muhit
Lisan al Arab, al Qaamuus al Muheet, Maqaayees Allugha, al Sahaah fil lugha and al AAbaab al Zaakhir
1)
E.W.
Lane's Arabic-English lexicon FREE online and on disc
2) E.W. Lane's Arabic-English lexicon (for slow connections only)