qtrans is an offline dictionary (word translator written in Qt5/KF5).
It uses Babylon (*.dic, *.bgl), StarDict (*.dict, *.dict.dz: *.ifo), Dictd and FreeDict (*.dict, *.dict.dz: *.index) as well as plain text (*.dic.txt) dictionaries. Plain text dictionaries should have the format: "expression [tab] definition".