It means, that it is hidden. Some dictionaries do not use this field as there are only original words and translations. On the right of the original-word field you can find a splitter. Drag it to the left to show the transcription field. You can change the size of text boxes by dragging the splitters or by changing the size of the window.
Here you can see the splitter to the right. The transcription field is hidden.
Here the transcription field is not hidden.