Related Clues:

• One before bi
• Tri- less two
• Prefix with -logy
• The first "T" of TNT
• The first 'T' in 36-Down
• Prefix with brow
• Form intro
• See 64A
• Lateral or cycle lead-in
• Prefix with ''sect''
• Iso- kin
• Prefix with state or angle
• Iso-
• Single starter
• One more than bi-