sub ‧ sis ‧ tence /səbˈsɪst ə ns/ BrE AmE noun [uncountable]
1 . the condition of only just having enough money or food to stay alive:
Many of the families are forced to live at the subsistence level.
The land provided subsistence and little more.
2 . subsistence farming/agriculture etc farming that produces just enough food for the farmer to live on, but does not produce enough food to sell to other people
3 . subsistence allowance/payment etc money that is paid to someone so that they can buy meals, pay for a place to stay etc