Bear first sign of tailspin (5)
I believe the answer is:
teddy
'bear' is the definition.
(teddy bear is a stuffed toy)
I can't explain the rest of the clue.
(Other definitions for teddy that I've seen before include "plaything" , "Cuddly toy" , "Type of bear" , "Child's soft toy" , "A child's toy bear" .)