ruddle

As verbs the difference between ruddle and nuddle

is that ruddle is to mark something with red ochre while nuddle is (uk|dialect) to walk quickly with the head bent forward.

As a noun ruddle

is a form of red ochre sometimes used to mark sheep or ruddle can be a riddle or sieve.

As nouns the difference between taxonomy and ruddle

is that taxonomy is the science or the technique used to make a classification while ruddle is a form of red ochre sometimes used to mark sheep or ruddle can be a riddle or sieve.

As a verb ruddle is

to mark something with red ochre.