more than is usual, expected, or than exists already synonym additional Breakfast is provided at no extra charge. The conference is going to be a lot of extra work. an extra pint of milk The government has promised an extra £1 billion for health care. Take extra care on the roads this evening. The play is to run for an extra week! extra help for single parents see also extra time Word Origin mid 17th cent. (as an adjective): probably a shortening of extraordinary, suggested by similar forms in French and German.