Related Clues:

• Vital tube and main line
• Leaf rib; ore layer in rock
• Main traffic route
• Important transport route
• No way hors-d'oeuvre must precede variable main course
• Transporter heading off on unknown, vital route
• What sounds like empty-headed streak
• Distinctive quality, useless if pronounced
• Five-one to Germany - that shows style
• Vessel for claret wine filled with ultimate in Bourgogne
• Blood vessel; important route
• Style — bootless by the sound of it
• Distinctive style useless on the radio
• Main line of railway following a route that avoids centre of Slough
• The ear's puffed up — blood vessel visible