愛妾[aishou] beloved concubine
妾腹[shoufuku] illegitimate (e.g. born to a mistress)
妻妾[saishou] one's wife and mistress(es)
男妾[danshou] male paramour
妾出[shoushutsu] illegitimate (e.g. born to a mistress)

妾宅[shoutaku] house in which a mistress is kept
蓄妾[chikushou] keeping a mistress (concubine)
外妾[gaishou] foreigner's mistress
洋妾[youshou] Westerner's mistress

垂迹[suijaku] temporary manifestation by a buddha (in order to save people)
筆迹[hisseki] handwriting
真迹[shinseki] true autograph

事迹[jiseki] evidence
本地垂迹説[honjisuijakusetsu] manifestation theory (holding that Shinto gods are manifestations of buddhas)
迹門[shakumon] first half of the Lotus Sutra, in which the Buddha appears as a spatiotemporally restricted being