1. dull, dreary, sullen, depressed

expressions (phrases, clauses, etc.) adjective (keiyoushi)

2. dissatisfying, disappointing, lackluster, inadequate

adjective (keiyoushi) expressions (phrases, clauses, etc.)

3. unattractive, unappealing

expressions (phrases, clauses, etc.) adjective (keiyoushi)

4. boring, uninteresting

adjective (keiyoushi) expressions (phrases, clauses, etc.)