Is element FeO ionic or molecular?

First of all 'FeO' is NOT an element. It is a compound composed of two elements. The elements being iron(Fe) and oxygen(O).

Next, you appear to misunderstand between 'Ionic' and 'molecular'.

Any substance is a composed of two or more atoms is a molecule.

The method of combination of these atoms can be either 'Ionic' or 'covalent'.

Iron(II) Oxide (FeO) is an ionic molecule (compound).

Fe^(2+)(aq) + O^(2-)(aq) = FeO(s)