All of the following words--except one--are derived from the same root: maritime, marina, marinate, maroon, marinara, marine, mariner. Which one does not belong?

Marinate.

The root I would assume is mar, mari.

The obvious one it maroon, but it's not that one.

The root mar, mari means relating to the sea, ocean. (i think.)

Maritime, Marina, Maroon, Marine, and Mariner are in some way obviously connected to the sea.

Marinara and Marinate are the odd ones out.

Admittedly, I searched the answer up for these last two words.

Marinara comes from the word alla marinara, or sailor style.

So marinate is the odd one out.

i think.