I think his claim is completely groundless.

His claim is considered groundless.

This fish has a bland taste.

I like drawing pictures with this charcoal paper.

I bought charcoal for the barbecue.

He was hospitalized for cholecystitis.

I made a delicious custard cream using yolk.

He hiked the mountain alone.

His opinions are always extreme.

His opinions are always extreme, and he rarely takes a neutral stance.