tree·nail or tre·nail 
(trēnāl′, trĕnəl, trŭnəl) also trun·nel (trŭnəl)
(trēnāl′, trĕnəl, trŭnəl) also trun·nel (trŭnəl)n.
A wooden peg used as a fastener in building wooden ships or timber-frame buildings.
- sure enough
- sure-fire
- surefire
- sure-footed
- surefooted
- sure-footedly
- sure-footedness
- surely
- sureness
- sure thing
- surety
- surety bond
- suretyship
- surf
- surface
- surface-active
- surface dive
- surface diver
- surface diving
- surface-effect ship
- surface mail
- surface of revolution
- surface plate
- surface structure
- surface tension