Gulf Stream 
A warm ocean current which flows from the Gulf of Mexico parallel with the American coast towards Newfoundland, continuing across the Atlantic Ocean towards NW Europe as the North Atlantic Drift.
- athletic support
- athletic supporter
- athletism
- athlothete
- athlothetes
- at-home
- -athon
- Athonite
- a thorn in someone's side (or flesh)
- Athos, Mount
- athwart
- Athínai
- -atic
- a tight corner (or spot or place)
- atilt
- at interest
- at intervals
- -ation
- at issue
- at it
- at its (or someone's) worst
- Ativan
- -ative
- Atkins diet
- Atkinson, Sir Harry