weighty

Excessively fat.

“a weighty man”

Powerfully persuasive.

“a weighty argument”

Of great gravity or crucial import; requiring serious thought.

“the weighty matters to be discussed at the peace conference”

Weighing heavily on the spirit; causing anxiety or worry.

“weighty problems”

Having relatively great weight; heavy.

“a weighty load”

“a weighty package”