御祖父さん[ojiisan] grandfather
御父さん[otossan] father
異父[ifu] same mother, different father
家父長制[kafuchousei] patriarchal authority
外祖父[gaisofu] maternal grandfather

岳父[gakufu] (man's) father-in-law
杜父魚[tofugyo] sculpin (any fish of family Cottidae, inc. the bullheads and the miller's-thumb)
義父[gifu] father-in-law
教父[kyoufu] godfather
継父[keifu] stepfather

老麺[raamen] ramen (Chinese-style noodles)
家老[karou] chief retainer
棄老[kirou] old person thrown away in the mountains
敬老[keirou] respect for the aged
敬老の日[keirounohi] Respect-for-the-Aged Day Holiday (third Monday in September)

元老[genrou] elder statesman
元老院[genrouin] (Roman) senate
故老[korou] old people
車海老[kurumaebi] kuruma prawn (Marsupenaeus japonicus)
寿老人[juroujin] god of longevity