ground vs undercoat

ground and undercoat both are nouns.

Word	Noun	Adjective	Verb	Adverb
ground	Yes	No	Yes	No
undercoat	Yes	No	Yes	No

As nouns, ground and undercoat are synonyms defined as:

ground and undercoat: the first or preliminary coat of paint or size applied to a surface

Other synonyms of ground include flat coat, primer, primer coat, priming, priming coat.

As verbs, ground and undercoat are synonyms defined as:

Other synonyms of ground include prime.

ground (noun)	undercoat (noun)
the first or preliminary coat of paint or size applied to a surface	thick soft fur lying beneath the longer and coarser guard hair
(art) the surface (as a wall or canvas) prepared to take the paint for a painting	the first or preliminary coat of paint or size applied to a surface
a connection between an electrical device and a large conducting body, such as the earth (which is taken to be at zero voltage)	seal consisting of a coating of a tar or rubberlike material on the underside of a motor vehicle to retard corrosion
the part of a scene (or picture) that lies behind objects in the foreground
a relatively homogeneous percept extending back of the figure on which attention is focused
a position to be won or defended in battle (or as if in battle)
a rational motive for a belief or action
the solid part of the earth's surface
material in the top layer of the surface of the earth in which plants can grow (especially with reference to its quality or use)
a relation that provides the foundation for something
the loose soft material that makes up a large part of the land surface

ground (verb)	undercoat (verb)
use as a basis for; found on	cover with a primer; apply a primer to
instruct someone in the fundamentals of a subject
place or put on the ground
confine or restrict to the ground
connect to a ground
cover with a primer; apply a primer to
fix firmly and stably
(baseball) a hit that travels along the playing field.
throw to the ground in order to stop play and avoid being tackled behind the line of scrimmage
hit or reach the ground
bring to the ground