noun
plural sixes
[count] :the number
[count] :the sixth in a set or series
[noncount] :six o'clock
at sixes and sevens
chiefly Brit informal :disorganized and confused
hit/knock (someone) for six
Brit informal :to have an unpleasant and shocking effect on (someone)
six of one, half (a) dozen of the other
US or chiefly Brit six of one and half a dozen of the other
informal - used to say that you do not see any real difference between two possible choices
US