Unintelligent

extremely unintelligent or lacking in common sense

Don't bother asking her for help with math.She's about as dumb as a coal bucket when it comes to numbers.

an individual who often breaks things or makes mistakes in situations that require thoughtful behavior or thinking

Her energetic dancing was like a bull in a china shop, narrowly avoiding collisions with other dancers and nearly knocking over props.

someone who can be easily taken advantage of

Because he was known as a soft touch, his friends frequently borrowed money from him and rarely paid it back.

an individual who is easily deceived or influenced

Don't bother discussing politics with him; he's a nose of wax, changing his views depending on who he's talking to.

to be easily fooled due to one's lack of experience or judgment

Don't try to pull that trick on me.I wasn't born yesterday, you know.

used to describe someone who can be easily taken advantage of because their will is not strong enough

He talked tough, but when it came to taking action, his resolve was weak as water.

used to refer to someone who is not paying attention or is not intelligent enough

During the meeting, he just sat there with a blank expression, as if the lights were on, but nobody was home.It was clear he wasn't paying attention.

to be smart or experienced enough to find one's way out of a problematic situation

Even a dog knows enough to come out of the rain, Charlie.

someone whose behavior is marked by foolishness or ignorance

He forgot his keys for the fifth time this week.What a dumb bunny!

used to describe someone who shows a great lack of intelligence or good judgment

He thought he could fix the car without any knowledge of mechanics.He's thick as two short planks when it comes to automobiles.

used to describe someone who behaves in a very foolish or crazy manner

He believes in conspiracy theories and wears a tinfoil hat.He's as daft as a brush!

a derogatory expression used to describe a person who relies solely on physical strength or brute force, without demonstrating any intelligence, skill, or strategic thinking

He may be a great athlete, but when it comes to critical thinking, he's all brawn and no brain.

(of a person) to understand things very quickly

During the training session, John proved to be quick on the uptake.He learned the software's features and functionality in no time.

to lack intelligence or rationality

After his strange explanation for the missing files, it's clear he's not playing with a full deck.