1) Bent again 2) Curved 3) Curved backward or inward 4) Curving 5) Recurvate 1) Curved 2) Curving 3) Recurvate 
bent or curved backwards or downwards.
curved outward or downward
curved backwards or downwards
• (a.) Curved in an opposite or uncommon direction; bent back; as, a bird with a recurved bill; flowers with recurved petals.
Bent backwards.
curved backwards or outwards
Curved or curled downwards or backwards. ... (09 Oct 1997) ... 
Bent backwards, usually of sepals.
Curved or bent backward.
curved backwards or outwards
Curved downward or backward.
curved backward.
Bent or curved backwards
Curved upward (as in the bill of American Avocet).
Re·curved' adjective Curved in an opposite or uncommon direction; bent back; as, a bird with a recurved bill; flowers with recurved petals. 
Bent or curved backwards
Bent or curved downward or backward.
curved backwards or downwards
curved upward toward tip
Curved upward or backward (as in a deformed bill.)
Curved as an arc having its ends behind its center.
recurvate adjective curved backward or inward
(of bill) Upcurved (e.g. as Pied Avocet and Terek Sandpiper).