1. A person who is inexperienced, incompetent, or regarded as foolish or contemptible.
Usage: slang; informal; often derogatory
2. In surfing, a person who is not a skilled or experienced surfer.
Usage: slang; surfing jargon

Examples

• He made such a gomer move by showing up late to the meeting.
• The gomer tried to paddle out in waves way too big for his skill level.
• Don't be such a gomer—you had one job to do.
• That gomer crashed into three people on the beach.
• She called him a gomer after he forgot his own birthday.