Kelime.com (Osmanlıca sözlük)

6 different dictionaries (Kâmûs-i Türkî, Lexicon (Redhouse), Vankulu Lugatı, Kâmûsu’l-Muhit, names dictionary and appendix) were combined to form this  Ottoman Turkish dictionary, containing more than 450.000 entries and around 1 million phrases. 

Kelime.com database for access