Possible Clues:

• The thing is that it sounds more like 14 down
• Sound more amphibious? That's it!
• Is this to have a tune with 'er? That's what it is
• It it is comparatively amphibious, more like, by the sound of it
• That's what it is: more of an amphibian, by the sound of it
• It sounds more than amphibious
• That makes it sound more amphibious
• Tom previously having no interest in the Queen
• Fresh-sounding expression a little defective for gender
• Non-21 description of Livingstone, say?