Definition of add up
1 a : to come to the expected total <the bill doesn't add up> b : to form an intelligible pattern : make sense <her story just doesn't add up>
2 a : amount 1b —used with to <the play adds up to a lot of laughs> b : 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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