せすじ 背筋 Common word Show 1 collocation 背筋を伸ばす - to straighten up one's back (e.g. stand up straight, sit up straight) LinksSentence search for 背筋Sentence search for せすじSentence search for 背すじKanji details for 背 and 筋Edit in JMdict Noun1. spine; line of the backboneそれをみ見てうれしくてせすじ背筋がぞくぞくした。The sight sent chills of delight up my spine.Noun2. seam down the back (of clothing)Other forms背すじ 【せすじ】 Discussions Log in to talk about this word.