Proto-South Dravidian : *ar-
Meaning : rare
Tamil : aru (arum, ār)
Tamil meaning : rare, difficult, etc.
Tamil derivates : aritu that which is difficult, rare, precious; ariya difficult; arumai rareness, smallness; difficulty; arumanta rare, precious; aruku (aruki-) to become scarce, diminished, be reduced, happen rarely, disappear; arukku (arukki-) to make scarce, reduce, put a stop to, destroy; regard as precious; n. scarceness; arukkam smallness, brevity; arukkāṇi rareness, preciousness; aruŋku, aruntal, aruvam rareness; aruppam difficulty, fort; (PPTI) aruppu the natural protection of a forest; arakku (arakki-) to cause to diminish; āri difficulty; āriya little, delicate
Malayalam : aru
Malayalam meaning : rare, unusual, impossible
Malayalam derivates : ariya rare, uncommon; aruma, arima superiority, importance; difficulty; arippam difficulty; arutu what ought not to be, impossibility; arukuka to diminish
Kannada : aradu, aridu, arudu
Kannada meaning : that is impossible, wonderful, great or important
Tulu : arkuni
Tulu meaning : to become less, be humbled, depressed
Notes : Tamil forms with the long vowel (āri, āriya) are not backed up by any other evidence and have to be considered secondary.
Number in DED : 0221
