What are some six letter words with 1st letter A and 2nd letter B and 3rd letter A and 4th letter C?

According to SOWPODS (the combination of Scrabble dictionaries used around the world) there are 2 words with the pattern ABAC--. That is, six letter words with 1st letter A and 2nd letter B and 3rd letter A and 4th letter C. In alphabetical order, they are:

abacas

abacus