A negative that is underexposed and normally developedhas little or no detail in the shadow areas that are important to the subject. It is described as "thin". The highlight areas will be rich , transparent and full of detail but they will render as depressed muddy greys instead of bright highlights.
What do underexposed negatives look like?
When a film is underexposed the negative will have a pale see through appearance. These transparent areas will appear black on the print, but the brightest highlight areas will still have detail. ... An overdeveloped film produces rich black negatives that print with too much contrast and increased grain.
What does it mean if film is negative?
In photography, a negative is an image, usually on a strip or sheet of transparent plastic film, in which the lightest areas of the photographed subject appear darkest and the darkest areas appear lightest.