sponsion /sponˈshən/

1. The act of becoming surety for another
2. An agreement or promise made on behalf of another, esp by an individual on behalf of his or her government

sponˈsional adjective

• thumb knot
• thumb knots
• thumb latch
• thumb latches
• thumbless
• thumblike
• thumbling
• thumblings
• thumb mark
• thumb-marked
• thumb marks
• thumbnail
• thumbnails
• thumbnail sketch
• thumbnut
• thumbnuts
• thumb one's nose
• thumb piano
• thumb pianos
• thumbpiece
• thumbpieces
• thumbpot
• thumbpots
• thumbprint
• thumbprints