knag /nag/

1. A knot in wood
2. A peg

• fastish
• fast lane
• fast lanes
• fastly
• fastness
• fastnesses
• fast neutron
• fast neutrons
• fast reactor
• fast reactors
• fasts
• fast stream
• fast streams
• fast-talk
• fast-talked
• fast-talking
• fast-talks
• fast track
• fast-track
• fast-tracked
• fast-tracker
• fast-trackers
• fast-tracking
• fast tracks
• fast-tracks