Regularly taken from ignorant old lecher (4)
I believe the answer is:
goat
'old lecher' is the definition.
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for goat that I've seen before include "Capricorn animal" , "Billy - nanny" , "Beast (of Capricorn)" , "Animal in zodiac" , "Butting nanny, perhaps?" .)