Billable is a 8 letter English word. It's valid Scrabble word worth 12 points. It's valid Words with friends word worth 17 points.
You can make 110 anagrams from letters in billable (abbeilll).
First recorded in 1570-80; bill1 + -able
Also, many counselors work on billable hours, so agencies don't lose much money if we take time off.
If your husband is earning $10 million a year, choosing the treadmill of billable hours really is rather bizarre.