An animal or bird that runs from left to right (5)
I believe the answer is:
lemur
'an animal' is the definition.
(lemur is a kind of animal)
'bird that runs from left to right' is the wordplay.
I cannot quite see how this works, but
'bird' could be 'emu' (emu is a type of bird) and 'emu' is located in the answer.
'runs' could be 'r' (cricket abbreviation) and 'r' is found within the answer.
'left' could be 'l' (common abbreviation) and 'l' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'or' is the link.
Can you help me to learn more?
(Other definitions for lemur that I've seen before include "Tree-dwelling primate" , "Animal with foxy face and long furry tail" , "Arboreal animal" , "Nocturnal primate from Madagascar" , "Ring-tailed prosimian" .)