From 伸(の)ばし (nobashi, “lengthening, 連(れん)用(よう)形(けい) (ren'yōkei, “stem or continuative form”) of the verb 伸(の)ばす (nobasu, “to lengthen”).”) + 棒(ぼう) (bō, “stick”).
のばしぼう • (nobashibō)