無駄を省く
むだをはぶく to exclude wastefulness

無駄口
むだぐち chatter idle talk

無駄死に
むだじに dying in vain

無駄花
むだばな blossom which fails to produce fruit

無駄話
むだばなし gossip idle talk chat

無駄足
むだあし visit for no reason go on fool's errand

無駄遣い
むだづかい waste money on squander money on flog a dead horse

無駄食い
むだぐい eating between meals living idly

無駄飯
むだめし living idly

無駄骨
むだぼね useless waste of time and effort pointless vain efforts

無駄骨折り
むだぼねおり laboring in vain or for no result