E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Execrate (3 syl.).
To many Roman laws this tag was appended, If any one breaks this law, sacer esto, i.e. let his body, his family, and his goods be consecrated to the gods. When a man was declared sacer, anyone might kill him with impunity. Anyone who hurt a tribune was held a sacer to the goddess Cers. Ex in this word is intensitive.
If anyone hurt a tribune in word or deed, he was held accursed [sacer], and his goods were confiscated.Livy, iii. 55; see also Dionysius, vi. 89, and viii. 17.