Insect eggs land oddly when thrown (5-4-4)
I believe the answer is:
daddy-long-legs
'insect' is the definition.
(I've seen this before)
'eggs land oddly when thrown' is the wordplay.
'when thrown' indicates anagramming the letters.
'eggs'+'land'+'oddly'='eggslandoddly'
'eggslandoddly' is an anagram of 'DADDY-LONG-LEGS'.
(Other definitions for daddy-long-legs that I've seen before include "Cranefly" , "Gladly send dog (anag) - kind of fly" , "Crane fly" .)