What is the meaning of Latin iaceo?

Answer 1

Iaceo (or, since the invention of the letter j, often jaceo) means "I lie" or "I am lying" - in the sense of being stretched out on a surface, not of being untruthful. It is the first-person singular present active indicative of the verb iacere (jacere), "to lie".

This word is not to be confused with iacio/jacio, which means "I throw". The infinitive of the two verbs is spelled the same, but the infinitive "to lie" has a long e in the infinitive ending. Consequently iacēre "to lie" is pronounced with an accent on the second syllable, while in iacere "to throw" the accent is on the first syllable. (Both are three-syllable words; the initial i/j is a consonant.)