偏芯[henshin] eccentricity (in mechanics, electronics, etc.)
燈芯[toushin] (lamp) wick
帯芯[obishin] thick obi sash
摘芯[tekishin] thinning (buds and branches)
芯地[shinji] padding

替え芯[kaeshin] spare lead
鉛筆の芯[enpitsunoshin] lead of a pencil
硬の芯[kounoshin] hard pencil lead
林檎の芯[ringonoshin] core of an apple

衿元[erimoto] front of neck
衿足[eriashi] nape of neck
衿裏[eriura] lining of the collar
半衿[haneri] neckpiece (on a kimono)

衿芯[erishin] collar core (stiff fabric, etc. inside a collar)
衿下[erishita] usu. the drop between collar and bottom hem on kimono, yukata, etc.
衿先[erisaki] collar points