Khichdi is a very highly used, common Hindi word, with its meaning changing according to the usage even though the basic meaning of the word remains the same all the time.
Basically Khichdi means a mixture in which there is no fixed ratio of contents defined. The word is most used for a dish where we mix daal (pulses) and rice and boiled together with spices and some more ingredients which may again vary. Besides, a mixed language, or greying here or anything hotchpotch may be called Khichdi. End of the day, khichdi is something in which you're never able to decide much.