Here's what rhymes with diminishing.

Consider these alternatives

diminished / finished decreasing / increasing shrinking / thinking increasing / leaving lessened / present eroded / noted dwindle / simple decreases / increases maximizing / rising waned / change thereby / by likelihood / should reducing / producing rising / driving waning / training expanding / understanding minimizing / rising depleting / meeting maximize / size growing / going undermined / mind dramatically / automatically slowing / going erosion / chosen reduces / uses