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

• true-blue
• true-born
• true-bred
• trued
• true dagga
• true-devoted
• true-disposing
• true-hearted
• true-heartedness
• trueing
• true-life
• truelove
• true-love grass
• true-love knot
• true-love knots
• true-lover's knot
• trueloves
• trueman
• truemen
• trueness
• truenesses
• true north
• truepennies
• truepenny
• truer