(1) Faults.  (2) Shortcomings.  (3) Impurities. 

Dosh may be of many types, one of them is --

Bhakshya Dosh
Bhakshya means worth eating means food, and Dosh means fault or defect. The term is used, not as regards the quality of food so much as the place where it is eaten, with whom it is eaten, and in whose presence it is eaten. Some consider that their food is polluted by being taken out of the Chaukaa (where the food is cooked) or that enclosed space where it is cooked and so forth.

Who eat "Chaukaa food" they draw a line from flour, or soft coke or chalk to enclose themselves and eat in that space only. while they eat in that space nobody can go in there or touch anything inside it. If they have to take any thing from outside, either they take it before entering it, or somebody has to pour it in their bowl or plate. If anything is touched anyhow, they leave the food then and there considering it impure. In fact this happens with "Kachchaa food" (Rotee or Phulkaa, Daal, rice etc food are called Kachchaa food) not with vegetables, or yogurt preparation, Parathaa, Pooree, or any fried thing etc.