As used in law, this word generally signifles the technical terms and phrases appropriate to particular instruments, or aptly fitted to the expression of a particular Intention in legal instruments. See the subtitles following. Words of art. The vocabulary or terminology of a particular art or science, and especially those expressions which are idiomatic or peculiar to it. See Cargill v. Thompson, 57 Minn. 534, 59 N. W. 638. Words of limitation. See LIMITATION. Words of procreation. To create an estate tail by deed, it is necessary that words of procreation should be used in order to confine the estate to the descendants of the first grantee, as in the usual form of limitation, “to A. and the heirs of his body.” Sweet Words of purchase. See PURCHASE.