ponderous

Having great weight.

Slow and labored because of great bulk or weight.

Difficult to maneuver or control because of great bulk or weight.

Slow or difficult to manage, especially because of complexity.

Dull and lacking grace or fluency: synonym: heavy.

Having weight; weighty; heavy; especially, very heavy; hence, clumsy or unwieldy by reason of weight: used both literally and figuratively.

Weighty; important; momentous.

Disposed to ponder; thinking; thoughtful.

Very heavy; weighty