What is Words Of Art?

Legal Definition
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.
-- Black's Law Dictionary
Legal Definition
Words used in a technical sense; words scientifically fit to carry the sense assigned them.
-- Black's Law Dictionary
Legal Definition
Technical terms.
-- Ballentine's Law Dictionary