irreverence (n.)youdaoicibaDictYouDict
mid-14c., from Latin irreverentia "want of reverence, disrespect," from irreverentem (nominative irreverens) "disrespectful, irreverent," from assimilated form of in- "not, opposite of" (see in- (1)) + reverens, present participle of revereri "to stand in awe of" (see revere).
reverence (n.)youdaoicibaDictYouDict
late 13c., from Old French reverence "respect, awe," from Latin reverentia "awe, respect," from revereri "to stand in awe of, respect, honor, fear, be afraid of; revere," from re-, intensive prefix (see re-), + vereri "stand in awe of, fear, respect," from PIE *wer-e-, suffixed form of root *wer- (4) "to be or become aware of, perceive, watch out for" (see ward (n.)).