plank vs plank over

plank is a noun but plank over is not a noun.

Word	Noun	Adjective	Verb	Adverb
plank	Yes	No	Yes	No
plank over	No	No	Yes	No

As verbs, plank and plank over are synonyms defined as:

plank (noun)	plank over (noun)
an endorsed policy in the platform of a political party
a stout length of sawn timber; made in a wide variety of sizes and used for many purposes

plank (verb)	plank over (verb)
cook and serve on a plank	cover with planks
cover with planks
set (something or oneself) down with or as if with a noise