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

育ての親[sodatenooya] foster parents
育て親[sodateoya] foster parent
１等親[ittoushin] first-degree relative
仮親[karioya] adopted parents
近親[kinshin] near relative

近親婚[kinshinkon] consanguineous marriage
近親相姦[kinshinsoukan] incest
懇親[konshin] friendship
懇親会[konshinkai] friendly reunion
似非親[eseoya] distant disinterested parent