What does it mean to evaluate a vector field on a 2-form?

For example, I've read the definition of the interior product a dozen times, Interior product - Wikipedia, the free encyclopedia , but my understanding is that a 2-form is something that eats two tangent vectors and spits out a number. A vector field on a manifold is a map v(x) = (x,u) for x in M and u in T_xM, so I don't understand how to plug a map into a form.

My guess would ge the following. So, as you've noted a vector field is just a section (smooth as you please) of the tangent bundle. So, now, if you instead think about the map $ defined by . You see then that if then you can think about defined by . That's my best guess without more context.

Yes a 2-form eats two vectors and outputs a number, but if you only feed one input it outputs a map:
defined by