n. 25B6; noun
his grandfather lives here : informal grandad, grandpa, gramps, grampy, grandaddy.
the grandfather of modern liberalism : FOUNDER, inventor, originator, creator, initiator; father, founding father, pioneer.
our Victorian grandfathers : FOREFATHER, forebear, ancestor, progenitor, antecedent.
25B6; verb (N. Amer. informal) some smokers have been grandfathered : EXEMPT, excuse, free, exclude, grant immunity, spare, absolve; informal let off (the hook).