shibboleth /shibˈə-leth/

1. The criterion, catchword or catchphrase of a group, party or sect by which members may be identified
2. A slogan
3. A peculiarity of speech
4. The Gileadite test-word to distinguish an Ephraimite, who could not pronounce sh (from Bible, Judges 12.5–6)
5. Any such test

• atabals
• atabeg
• atabegs
• atabek
• atabeks
• at a blow
• atabrin
• atabrins
• atacamite
• atacamites
• atactic
• at a discount
• ataghan
• at a glance
• atalaya
• atalayas
• at all
• at all costs
• at all events
• at all hours
• a tall man of his hands
• at all points
• at a loose end
• at a loss
• at a low ebb