اجصإِجَّاصٌ [The plum;] a certain fruit, (K, TA,) of the description termed فَاكِهَة, (TA,) well known; (Msb, K;) cold and moist; or, as some say, of moderate temperature; (TA;) which facilitates the flow of the yellow bile; (K;) i. e., its juice, or water, does so, when drunk with sugar-candy (طَبَرْزَذ) and manna (تَرَنْجُبِين) added to it; (TA;) and allays thirst, and heat of the heart; (K;) but it relaxes the stomach, and does not agree with it; and it generates a watery mixture; and its injurious effect is repelled by the drinking of sugary سِكَنْجُبِين [or oxymel]: it is of several kinds: (TA:) [the most common is the Damasc, or Damascene, plum:] the best is (K, TA) the Armenian, (TA,) that which is sweet and large: (K, TA:) the sour, or acid, is less laxative, and more cold: (TA:) the n. un. is with ة: (S, Msb, K:) you should not say إِنْجَاصٌ; (Yaakoob, S, K;) or this is a word of weak authority, (K, TA,) and you say إِجَّاصٌ and إِنجَاصٌ like as one says إِجَّارٌ and إِنْجَارٌ: (TA:) in the dial. of the Syrians, the إِجَّاصٌ [or إِنْجَاص or إِنجَاس accord. to common modern usage among them] is the [pear which they formerly called] مِشْمِش and [which others call] كُمَّثْرَي: (K:) it is of the growth of the country of the Arabs: (AHn:) اجّاص is an adventitious word, (S, K,) or arabicized, (Msb,) because ج and ص do not both occur in any Arabic word: (S, Msb, K:) or, accord. to Az, they do so occur; as, for instance, in حَصَّصَ, and in صَجٌّ. (TA.)