ridiculous

Shallow-brained is likely misspelled.

Shallow-brained has no English definition.

As an adjective ridiculous is

deserving of ridicule; foolish; absurd.

Ridiculous is a related term of queer.

As adjectives the difference between ridiculous and queer

is that ridiculous is deserving of ridicule; foolish; absurd while queer is (now|slightly|dated) weird, odd or different; whimsical.

As a noun queer is

(colloquial) a person who is or appears homosexual, or who has homosexual qualities.

As a verb queer is

to render an endeavor or agreement ineffective or null.

As an adverb queer is

queerly.

Simple is a related term of ridiculous.

As adjectives the difference between simple and ridiculous

is that simple is uncomplicated; taken by itself, with nothing added while ridiculous is deserving of ridicule; foolish; absurd.

As a noun simple

is (medicine) a preparation made from one plant, as opposed to something made from more than one plant.

As a verb simple

is (transitive|intransitive|archaic) to gather simples, ie, medicinal herbs.

Ridiculous is a related term of outlandish.

As adjectives the difference between ridiculous and outlandish

is that ridiculous is deserving of ridicule; foolish; absurd while outlandish is bizarre, strange.

As a noun chortle

is a joyful, somewhat muffled laugh, rather like a snorting chuckle.

As a verb chortle

is to laugh with a chortle or chortles.

As an adjective ridiculous is

deserving of ridicule; foolish; absurd.

Foolhardy is a related term of ridiculous.

As adjectives the difference between foolhardy and ridiculous

is that foolhardy is marked by unthinking recklessness with disregard for danger; bold but rash; hotheaded while ridiculous is deserving of ridicule; foolish; absurd.

Injudicious is a related term of ridiculous.

As adjectives the difference between injudicious and ridiculous

is that injudicious is showing poor judgement; not well judged while ridiculous is deserving of ridicule; foolish; absurd.

Ridiculous is a related term of simpleminded.

As adjectives the difference between ridiculous and simpleminded

is that ridiculous is deserving of ridicule; foolish; absurd while simpleminded is stupid.

Childlike is a related term of ridiculous.

As adjectives the difference between childlike and ridiculous

is that childlike is innocent and trustful; credulous; artless while ridiculous is deserving of ridicule; foolish; absurd.

As adjectives the difference between ridiculous and amazing

is that ridiculous is deserving of ridicule; foolish; absurd while amazing is causing wonder and amazement; possessing uniquely wonderful qualities.

As a verb amazing is

.