tamasa / tamoguna / tamasic | तम / तमोगुण / तामसिक
tamasa (Devanagari: तम ISO15919: tamasa) means darkness. tamoguna (Devanagari: तमोगुण ISO15919: tamoguṇa) is the material mode of demonic dark tendencies.
tamasic (Devanagari: तामसिक ISO15919: tāmasika) is an adjective which is used to describe the things that influence the mind to have dark tendencies.