Words

Arabic
ṯuknat- - pearl necklace; dyed wool collar that hangs as an ornament on the camel's neck (BK 1 231)

presumably related with assimilation of *m > n after the velar. As for the semantic shift, see SED I, No. 15

Arabic
ṯallat-, ṯilal-, ṯilāl- - flock of sheep or goats (BK 1 232, Lane 346)
Arabic
ṯalāṯ- - three (Lane 347)
Arabic
ṯulāṯāˀ - Tuesday (Lane 348)
Arabic
ṯalǯ- - snow (Lane 350)
Arabic
ṯūm- - garlic (Lane 365)
Arabic
ṯamma - there (Lane 350)
Arabic
ṯumma - then, afterwards (Lane 351)
probably, to be analyzed as *ṯin-ma, tracing it back to the numeral *ṯin-ā ‘two’ with a plausible semantic shift: “afterwards” < “another time, again.” (Kogan 2015: 202)
Arabic
ṯamāniⁿ - eight (Lane 355)
Arabic
ˀiṯnāⁿ - two (Lane 359)