Origin uncertain. Comparison with Arb.
ˀsn ‘to be altered, long standing, rancid (water)’ and
snn (IV) ‘to be advanced in age’ suggested in Tropper 2000:109, albeit semantically attractive, is undermined by the irregular phonological correspondence. DRS 658 compares Arb.
ṯnn (IV) ‘to become wasted and worn out (an old man),’
ṯinn- ‘dry herbage’. Cf. also Arb.
wṯn (X) ‘to become numerous, abundant’ (Kogan 2015: 316)