काँजी kāṁjī is a Tamil borrowing into Hindi which means either a kind of vinegar made from rice, or mustard seed. or rice-water (McGregor 1993). This borrowing is via Sanskrit Kanjika कंजिका / कञ्जिका. But the word is ultimately derived from கஞ்சி (kanji) which literally means ‘boiled things’ in Old Tamil, but in its contemporary sense means Rice Gruel or starch. Interesting to know that popular East Asian dish made of rice named “Congee” is also derived from Tamil ‘Kanji‘ which traveled into English through Portuguese. This Congee is also known as kanni in Malayalam and Ganji in the Kannada / Telugu.
Not to forget the popular fermented drink of north western India – kanji vada (कांजी वड़ा).
The word kānjï hāus कांजी हाउस (enclosure for stray cattle) in Hindi has its connection with words for “rice water / gruel” in Dravidian languages – Tamil kañci; Kodagu kañji, Kannada gañji etc.
This interesting connection is because of British-Indian army practice of having temporary confinement area for drunk / unruly soldiers where the staple diet was rice gruel / starch water for the period of stay. They were so named “Congee houses”.
This sense was further extended for keeping stray / lost cattle in an enclosure by the British administration in north India.
Linguistica Indica 