Very reliable and dependable
Extremely thick and heavy, so as to make it impossible to move.
Dependable, loyal, reliable, trustworthy.
Strongly built; also, in good or strong condition.
Not permitting water or some other liquid to escape or penetrate; watertight.
Staying true to one's aims or principles; firm, resolute, unswerving.
Impermeable to air or other gases; airtight.
Of a hunting dog: that can be depended on to pick up the scent of, or to mark, game.
Synonym of afterdamp (“suffocating gases present in a coal mine after an explosion caused by firedamp”)