Definition of add up
1a : to come to the expected total the bill doesn't add upb : to form an intelligible pattern : make sense her story just doesn't add up
2a : amount 1b —used with to the play adds up to a lot of laughsb : to amount to a lot just a little each time, but it all adds up
: to form an opinion of added him up at a glance
First Known Use of add up
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