change over, convert - change from one system to another or to a new plan or policy; "We converted from 220 to 110 Volt"

lapidify, petrify - change into stone; "the wood petrified with time"

senesce, age, maturate, mature, get on - grow old or older; "She aged gracefully"; "we age every day--what a depressing thought!"; "Young men senesce"