godan verb (-ru)
become scarce; run short
Describes a gradual or eventual shortage of something, often resources, supplies, or abstract things like patience.
水が乏しくなってきた。
Water has become scarce.
資金が乏しくなり、計画は中止された。
Funds ran short and the plan was canceled.
Derived from the adjective 乏しい (とぼしい, 'scarce') with the verb なる ('to become').