１．差別的意思，亦即事物彼此差別而無混雜。２．性的意思，亦即事物固有的本體。

陳義孝編, 竺摩法師鑑定, 《佛學常見辭彙》

界 (dhātu). "world," "realm." (1) Boundary, environment, realm. For example, the 'three realms' of desire, form and formlessness. (2) World. (3) The essential nature of the individual existence of things, as for example in the term fajie 法界. Essence, substance, original nature. The aspect of things as inherent, inborn from previous lifetimes, as opposed to conditioning from the present lifetime. (4) That which supports or sustains. Principle. (5) Discrimination; that which discriminates this and that, giving order in place of confusion. (6) Category, class, species; delimitation, division, kind, type. (7) Element. The compositional elements of human existence, or of perception. (8) The 18 realms 十八界, that is the 18 compositional elements of human existence: the six faculties, the six objects and the six cognitive functions. (9) The compositional elements of the universe: earth, air, water, fire, wind and consciousness. (10) 'Seeds.' In both Huayan and Consciousness-only theory, the seeds in the ālaya-vijñāna are sometimes called 界, meaning 'element' or 'cause.'

梵語 dhātu 之意譯。音譯為馱都，含有層、根基、要素、基礎、種族諸義。(一)界為各種分類範疇之稱呼，如：眼、耳、鼻、舌、身、意等六根，對色、聲、香、味、觸、法等六境，而產生眼識、耳識、鼻識、舌識、身識、意識等六識，合稱為十八界。又如地、水、火、風、空、識稱為六界。此外，欲界、色界、無色界稱為三界；此「界」有接近於「境界」之意。唯識宗即將一切法之種子稱為「界」，有要素、因之意。〔雜阿含經卷十二、相應部因緣篇第一、六十華嚴經卷五十八、法苑義林章卷五本〕
　(二)梵語動詞之語根，稱為字界。

佛光電子大辭典

p3889

dhātu. 馱都 Whatever is differentiated; a boundary, limit, region; that which is contained or limited, e. g. the nature of a thing; provenance; a species, class, variety; the underlying principle; the root or underlying principles of a discourse.

A Dictionary of Chinese Buddhist Terms, William Edward Soothill and Lewis Hodous

dhātu, avacara, sīmā; avacāra, āyatana, kṣetra, garbha, dvīpa, dhātuka, nibaddha, patha, bhāga, bhuvana, bhū-pradeśa, maṇḍala, loka, loka-dhātu, viṣaya, śīla.

佛教漢梵大辭典

P.2364-P.2369