PC

*ḥāmiy-(a)t- - wall (Blau 1957: 98, Marrassini 1971: 54‒56, Ginsberg 1973:134, Kogan 2015: 294)

is probably derived from PS *ḥmy ‘to watch, to protect’; to be reconstructed as an active participle *ḥāmiy-(a)t- on the joint evidence of Hebrew, El-Amarna and Ugaritic data if Arb ḥāmiyat- ‘mass of stones with which a well is cased’ and ḥāmiyeh - ‘courtyard’ are connected, it would push *ḥāmiy-(a)t- ‘walľ back to PCS

Ugaritic
ḥmt - wall (DUL 364‒365)
pl. ḥmyt reliably attested in syllabic writing as ḫa-mì-ti (Huehnergard 1987a:125)
Amarna Canaanite
ḫu(!)-mi-tu - wall, fortress (EA 141: 44)
a gloss to Akk. dūru
Phoenician
ḥmyt - wall, fortress (DNWSI 381)
pl.
Hebrew
ḥōmā - (city) wall (HALOT 298)
Moabite
ḥmt - wall, fortress (DNWSI 381)
Arabic
ḥāmiyat- - mass of stones with which a well is cased; all the stones of the casing of a well, matching one another (Lane 652)
Arabic
ḥāmiyeh - Hofraum (courtyard) (Behnstedt 288)
Yemenite
Qatabanian
tḥmy - wall (LIQ 63‒64)