- Per ardua ad astra
/pɜːr ˈɑːdjʊə æd ˈæstrə/ uknown 1. through difficulties to the stars: the motto of the RAF
[per an-uh m] /pər ˈæn əm/ adverb 1. by the year; yearly. /pər ˈænəm/ adverb 1. every year or by the year Latin, literally “by the year,” from per (see per) + annum, accusative singular of annus “year” (see annual).
[per-bawr-eyt, -bohr-] /pərˈbɔr eɪt, -ˈboʊr-/ noun, Chemistry. 1. a salt of perboric acid, as , NaBO 3 ⋅4H 2 O, used for bleaching, disinfecting, etc. /pəˈbɔːreɪt/ noun 1. any of certain salts derived, or apparently derived, from perboric acid. Perborates are used as bleaches in washing powders See sodium perborate
[per-bawr-uh ks, -aks, -bohr-] /pərˈbɔr əks, -æks, -ˈboʊr-/ noun, Chemistry. 1. .