groundless

As adjectives the difference between groundless and meritless

is that groundless is without any grounds to support it; baseless while meritless is without merit.

As adjectives the difference between arbitrary and groundless

is that arbitrary is (usually|of a decision) based on individual discretion or judgment; not based on any objective distinction, perhaps even made at random while groundless is without any grounds to support it; baseless.

As a noun arbitrary

is anything arbitrary, such as an arithmetical value or a fee.

As adjectives the difference between groundless and untenable

is that groundless is without any grounds to support it; baseless while untenable is not able to be held, as of an opinion or position; unholdable, indefensible.

As adjectives the difference between groundless and undefined

is that groundless is without any grounds to support it; baseless while undefined is lacking a definition or value.

As adjectives the difference between groundless and ungrounded

is that groundless is without any grounds to support it; baseless while ungrounded is not grounded.

As a verb ungrounded is

(unground).

As adjectives the difference between unprovoked and groundless

is that unprovoked is happening without provocation or motivation while groundless is without any grounds to support it; baseless.

Wrong is a related term of groundless.

As adjectives the difference between wrong and groundless

is that wrong is incorrect or untrue while groundless is without any grounds to support it; baseless.

As an adverb wrong

is (informal) in a way that isn't right; done incorrectly; wrongly.

As a noun wrong

is something that is immoral or not good.

As a verb wrong

is to treat unjustly; to injure or harm.

Groundless is a related term of improper.

As adjectives the difference between groundless and improper

is that groundless is without any grounds to support it; baseless while improper is unsuitable to needs or circumstances; inappropriate; inapt.

As a verb improper is

(obsolete|transitive) to appropriate; to limit.

Groundless is a related term of inaccurate.

As adjectives the difference between groundless and inaccurate

is that groundless is without any grounds to support it; baseless while inaccurate is mistaken or incorrect; not accurate.