1. in a way that shows lack of skill or experience; unprofessionally

Examples

• The play was performed amateurishly by the high school drama club.
• He painted the fence amateurishly, leaving streaks and uneven coverage.
• The website was designed amateurishly with poor navigation and clashing colors.
• She handled the interview amateurishly, stumbling over basic questions.
• The documentary was filmed amateurishly with shaky camera work.
• The repair was done amateurishly and broke again within a week.