塞源 （ソクゲン） blockage of a source

塞栓 （ソクセン） embolus, abnormal substance (i.e. air) circulating in the blood

梗塞 （コウソク） stoppage, tightness, block, infarction (e.g. cardiac)

閉塞 （ヘイソク） blockage, blockade, blocking up, stoppage, obstruction, occlusion

塞翁が馬 （サイオウガウマ） the future is unpredictable, inscrutable are the ways of heaven, the irony of fate

塞外 （サイガイ） outside a fort, outside the Great Wall of China

防塞 （ボウサイ） fort, defensive position

城塞 （ジョウサイ） fortress, stronghold, citadel

塞ぐ （ふさぐ） to stop up, to close up, to block (up), to plug up, to shut up, to cover (ears, eyes, etc.), to close (eyes, mouth), to stand in the way, to obstruct, to occupy, to fill up, to take up, to perform one's role, to do one's duty, to feel depressed, to be in low spirits, to mope