Agreement of conveyance

What does Agreement of conveyance mean in American Law?

The definition of Agreement of conveyance in the law of the United States, as defined by the lexicographer Arthur Leff in his legal dictionary is:

A term which could not be worse chosen any time it turns out (and the occasions are not rare) that an agreement to convey has different legal consequences from an actual conveyance, for the words are almost perfectly equivocal as to which is meant. Luckily, because of the doctrine of equitable conversion, less turns on the distinction than one would otherwise expect. See also deed. Cf agreement of sale.