Heavy, massive, weighty. / (figuratively, by extension) Serious, onerous, oppressive. / Clumsy, unwieldy, or slow, especially due to weight. / Dull, boring, tedious; long-winded in expression.

In a ponderous manner; very slowly. / With the appearance of great weight.

The quality of being ponderous.

plural of ponderousness

A person who ponders; a thinker.

plural of ponderer

To wonder, think of deeply. / To consider (something) carefully and thoroughly. / (obsolete) To weigh.

(colloquial) A period of deep thought.

(physics) Having a detectable amount of matter; having a measurable mass. / Worthy of note; significant, interesting. / (rare) Heavy; ponderous.

An act of rumination or cogitation.