Flier born to get out of line? (5)
I believe the answer is:
robin
'flier' is the definition.
(robin is a kind of birdanimal)
'born to get out of line?' is the wordplay.
'born' becomes 'b' (abbreviation next to the year of someone's birth).
'to get' indicates putting letters inside.
'out of line?' becomes 'roin' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'b' going into 'roin' is 'ROBIN'.
Can you help me to learn more?
(Other definitions for robin that I've seen before include "Bird - boy's name" , "Small brown and red bird" , "Bird; Batman's aide" , "Small songbird" , "Christmas songbird" .)