1. having the most bumps or uneven surfaces; most rough or jolting
Usage: superlative form of bumpy
2. most difficult or troubled; having the most problems or setbacks
Usage: figurative use

Examples

• This is the bumpiest road I’ve ever driven on.
• The back seat gave us the bumpiest ride during our trip.
• That was the bumpiest flight due to severe turbulence.
• Their relationship went through its bumpiest period last year.
• The project had its bumpiest phase during the first quarter.
• The bumpiest part of learning to drive is parallel parking.