myrtaceous,a.Bot.|mɜːˈteɪʃəs| [f.mod.L. Myrtāce-æ, fem.pl. of late L. myrtāceus (Celsus), f.myrt-us myrt: see -aceous.] Of the family Myrtaceæ, to which the myrtle belongs. 1835Penny Cycl. III. 123/2 Myrtaceous plants with white blossoms.1866Treas.Bot. 773/1 A myrtaceous tree.