Definition of buy in
- Be sure to buy in a lot of tinned food in case we're snowed up.
: to acquire possession, ownership, or rights to the use or services of by payment especially of money : purchase
: to obtain in exchange for something often at a sacrifice
: something of value at a favorable price
: an act of acquiring possession, ownership, or rights to the use or services of something by payment especially of money : an act of buying (see 1buy 1) : purchase
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