spur

noun

1.
a verbalization that encourages you to attempt something
goad goading prod prodding spurring urging
Derived from:
spur
2.
any sharply pointed projection
acantha spine
Derived from:
spur
3.
tubular extension at the base of the corolla in some flowers
4.
a sharp prod fixed to a rider's heel and used to urge a horse onward
spurrier gad
Derived from:
spur
5.
a railway line connected to a trunk line
branch line spur track