حصيIbn Fāris gives three related senses: prevention/restraint, counting and capacity, and a … (root hsy)

Al-ḥaṣā (الحصى): small stones/pebbles; [one says] 'three ḥaṣayāt (حصيات)', the singular being ḥaṣāh (حصاة). And al-ḥaṣā (الحصى) [also denotes]: a great number, likened to the pebbles of stones (حصى الحجارة) because of their abundance. Al-A'shā said: "I am not the more numerous of them in pebbles (ḥaṣā), for indeed glory belongs to the one who outnumbers." And ḥaṣāt al-rajul (حصاة الرجل): his steadiness/sound judgment; [and ḥaṣāt al-lisān (حصاة اللسان): its sharpness/eloquence]. He said: "And indeed a man's tongue, so long as it has no ḥaṣāh (حصاة) [restraining sense], is a witness against his shameful faults." And it is said: ḥaṣāt al-'aql (حصاة العقل) [the 'pebble' of the intellect], because a man reckons (yuḥṣī) by means of it against himself, so that he knows what he should do and what he should leave. Some people say aṣāh (أصاة) [instead]. And in the ḥadīth: "Are people thrown down upon their nostrils into Hell for anything but the ḥaṣā (reckoning/harvest) of their tongues?" And it is [also] said ḥaṣā'id (حصائد) [harvests]. And every piece of musk is called a ḥaṣāh (حصاة). And al-ḥaṣāh (الحصاة) [also]: a disease occurring in the bladder, whereby the urine thickens and hardens until it becomes like a stone (ka-l-ḥaṣāh). [When this happens] the man is ḥaṣiya (حصي), and he is maḥṣī (محصي). And al-iḥṣā' (الإحصاء): comprehensive knowledge attained by exhaustively counting a number.

Al-ḥaṣā (الحصى): small stones, the singular of which is ḥaṣāh (حصاة). Ibn Sīdah [said]: al-ḥaṣāh (الحصاة), among stones, is well-known, and its plurals are ḥaṣayāt (حصيات), ḥaṣan (حصى), ḥiṣiyy (حصي), and ḥuṣiyy (حصي). And the saying of Abū Dhu'ayb, describing a spear-thrust: "A gushing [wound] that sweeps the pebbles (al-ḥaṣā) from its path, the entrails of the terrified one flying forth as it pours out." He means: it flows so violently that, had there been pebbles there, it would have swept them away. And ḥaṣaytuhu bi-l-ḥaṣā (حصيته بالحصى), aḥṣīhi (أحصيه), means: I pelted/threw it at him. And ḥaṣaytuhu (حصيته) [also] means: I struck him with pebbles. Ibn Shumayl [said]: al-ḥaṣā (الحصى) is that which is flung with a flicking throw, and it is like sheep-droppings [in size]. Abū Aslam said: the large kind, like camel-droppings, is [also called] ḥaṣā. He said: Abū Zayd said: ḥaṣāh, ḥiṣiyy, ḥuṣiyy (حصاة وحصي وحصي), like qanāh, qiniyy, quniyy (قناة وقني وقني) and nawāh, nawiyy, nuwiyy (نواة ونوي ونوي) and dawāh, duwiyy (دواة ودوي). He said: thus Shamir recorded it in his own hand. He said: another [scholar] said one says ḥaṣāh and ḥaṣan (حصاة وحصى) with fatḥah on the first letter, and likewise qanāh and qanan (قناة وقنى) and nawāh and nawan (نواة ونوى), like thamarah and thamar (ثمرة وثمر) [a fruit and fruits]. He said: another [scholar] said one says nahr ḥaṣawiyy (نهر حصوي), meaning 'a river with much gravel,' and arḍ maḥṣāh and ḥaṣiyah (أرض محصاة وحصية), meaning 'a land abounding in pebbles,' and it is [said]: ḥaṣiyat taḥṣā (حصيت تحصى) [it became full of pebbles]. And in the ḥadīth: 'He forbade the sale of al-ḥaṣāh (بيع الحصاة, the pebble-sale).' It was said: this is when the buyer or seller says, 'When the pebble is thrown to you, the sale becomes binding.' And it was [also] said: it means saying, 'I sell you whichever of these goods your pebble lands upon when you throw it,' or 'I sell you land up to wherever your pebble reaches' — and all of this is invalid, being among the sales of the Jāhiliyyah [pre-Islamic era], and all such sales involve gharar (uncertainty) because of the ignorance [of exact terms] they contain. And al-ḥaṣāh (الحصاة) [also]: a disease occurring in the bladder, whereby the urine thickens and becomes so hard that it turns into something like a stone (ka-l-ḥaṣāh); [the man so afflicted] is ḥaṣiya (حصي), and he is maḥṣī (محصي). And ḥaṣāt al-qasm (حصاة القسم): the stone by which people apportion water among themselves in turn [when it is scarce]. And al-ḥaṣā (الحصى) [also]: a great number, by comparison to the abundance of pebbles among stones. Al-A'shā said, preferring 'Āmir over 'Alqamah: "And I am not the more numerous of them in pebbles (ḥaṣā), for indeed glory belongs to the one who outnumbers." And Ibn Barrī cited: "The tribes have already known that you are a chief, and that you are of a house whose pebble-count [numbers] is formidable." And their saying, 'We are more numerous than them in pebbles (ḥaṣā),' means 'in number.' And al-ḥaṣw (الحصو): withholding/prevention. Bashīr al-Furayrī said: "Do you not fear God, when you withheld from me (ḥaṣawtanī) my due without any offense, and when you troubled me?" Ibn al-A'rābī [said]: al-ḥaṣw (الحصو) is [also] colic pain in the belly. And al-ḥaṣāh (الحصاة) [also]: intelligence and sound judgment. It is said: huwa thābit al-ḥaṣāh (هو ثابت الحصاة) ['he is firm in ḥaṣāh'] when he is intelligent. And 'fulān dhū ḥaṣāh wa-aṣāh (فلان ذو حصاة وأصاة)' means: he has intellect and sound opinion. Ka'b ibn Sa'd al-Ghanawī said: "And I know, not merely by conjecture, that when a man's kinsman is humbled, he too is humbled; and that a man's tongue, so long as it has no ḥaṣāh (حصاة) [restraining sense], is a witness against his shameful faults." And al-Azharī attributed it instead to Ṭarafah, meaning: when the tongue is not accompanied by an intellect restraining it from unfolding into what is disliked, the tongue betrays [its owner's] fault by what it utters of shameful matters... [entry continues]