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

一重継ぎ[hitoetsugi] sheep bend (knot)
引継ぐ[hikitsugu] to take over
継合せる[tsugiawaseru] to join together
継接ぎ[tsugihagi] patching (and darning)
継足す[tsugitasu] to extend (e.g. a house)

継ぐ[tsugu] to succeed (someone in a business or inheritance)
継嗣[keishi] successor
継っ子[keishi] stepchild
継承[keishou] inheritance
継承者[keishousha] successor