More on isograms

isogram - a word in which the letters turn up an equal number of times.

first-order isogram

• each letter appears just once
• as in dialogue, lexicography, ambidextrously and uncopyrightable.

second-order isogram

• each letter appears twice only
• as in deed, Vivienne, Caucasus and intestines

third-order isogram

• each letter appears three times only
• as in deeded and geggee