Related Clues:

• Not robust, vocally
• Grassed up? That'll sound a bit thin
• Eager to trim leading edge of some river-banks
• Like some pipes, but prepared to have change of heart
• (Of person) tall and thin
• Intensely desirous to lose grammes, becoming tall and thin
• Thin, though full of vegetation
• Eyes bigger than stomach, missing starter to get thin
• (Of sound) thin in tone
• Lines about receding river abounding with grasses
• Politician in power gets bogged down?
• Boggy, marshy
• Shrill, or piping
• Long and thin, like hog's head removed
• Tall and thin, not starting with an enormous appetite