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

• good-humouredly
• good-humouredness
• good hunting
• goodier
• goodies
• goodiest
• goodiness
• goodinesses
• goodish
• good-King-Henry
• good-lack
• goodlier
• goodliest
• goodlihead
• goodliheads
• good-liking
• goodliness
• goodlinesses
• good-looker
• good-lookers
• good-looking
• good looks
• goodly
• goodlyhead
• goodlyheads