sunset clause
noun[C]
LAWukus(alsosunset provision)partof alaworcontractthatstateswhen it will end, or theconditionsunder which it will end:
Asunsetclausein thebillcalled for thetaxcutstoexpirein 2010.
The Pension Board haseliminatedthesunsetprovision,keepingtheprogramaliveindefinitely.