The Latin word for ‘tree,’ used as part of various names in Bot., Chem., etc.; as in Bot. arbor Judæ, the Judas tree (Cercis siliquastrum); in Chem. arbor Dianæ, the arborescent or tree-like appearance formed upon the introduction of mercury into a solution of nitrate of silver; arbor Saturni, the similar precipitate formed when a piece of zinc is put into a solution of acetate of lead; ARBOR VITÆ, q.v.
1669. Worlidge, Syst. Agric. (1681), 100. Trees that are planted … only for their Ornamental Habits … as Arbor Judæ, Laburnum, [etc.].
1741. Compl. Fam.-Piece, II. iii. 362. Transplant the Arbor Judæ.
