正せい四し面めん体たいMeaningsNoun1. regular tetrahedronKanji used正correct四four面surface体bodyPitch accentせいしめんたいComposed of正せい(logical) true; regular; 10^40; ten duodecillion; original; positive; greater than zero; thesis (in dialectics)Noun四しfour; 4Numeric面めん体たいfacepiece (of a respirator, etc.)Noun