triplicate
adj.
early 15c., "triple, threefold," from Latin triplicatus, past participle of triplicare "to triple," from tri- "three" (see tri-) + plicare "to fold" see ply, v.1).
v.
"to multiply by three," 1620s, from Latin triplicatus (see triplicate, adj.). Related: Triplicated; triplicating; triplication.