From Longman Dictionary of Contemporary Englishgood for somethinggood for somethinga) able to be used for a particular period of time SYN validgood for one month/a year etc Your passport is good for another three years. b) likely to continue living or being useful for a particular time or distance, even though old or not in good conditiongood for some time/a hundred miles etc This old truck is good for another 100,000 miles. c) informal likely to give you something or provide something Dad should be good for a few bucks. → good
Examples from the Corpus
good for something• Not much good for anything else.• So Princeton looked good for college until I met their pretentious admissions rep.• Life in Solano County had been good for him and Annette, he said.• This was good for his journalism.• The buffalo robes were good for keeping warm in carriages in northern cities.• The more physical the better for me.• Armed with inadequate information he usually fails to see why one moment is better for putting in a tack than any other.• She lost the first two babies, you know that, and she's always done her best for you. 