*Result of having no room under the beach umbrella for your knapsack?, 11 letters
Abandon one's efforts, slangily, 5 letters
Bring along lunch, slangily, 5 letters
Brown ___ (bring lunch), 5 letters
Just forget the whole thing!, 5 letters
Quit trying, in slang, 5 letters
Skip school, in slang, 5 letters
Stop trying, informally, 5 letters