sub ‧ sist /səbˈsɪst/ BrE AmE verb [intransitive]
[ Date: 1500-1600 ; Language: Latin ; Origin: subsistere 'to come to a stop, remain, exist' , from sistere 'to come to a stand' ]
1 . to stay alive when you only have small amounts of food or money SYN survive
subsist on
We had to subsist on bread and water.
Old people often have to subsist on very low incomes.
2 . especially law to continue to exist SYN survive