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

此の頃[konokoro] recently
一頃[hitokoro] once
何時頃[itsugoro] about when
近頃[chikagoro] lately
月頃[tsukigoro] these past months

見頃[migoro] best time to see
頃合い[koroai] suitable time
頃刻[keikoku] short period
今頃[imagoro] about this time
使い頃[tsukaigoro] handy