Sentence:  Like Sentinel and Nun, they keep / Their vigil on the green; / One seems to guard, and one to weep, / The dead that lie between; / And both roll out, so full and near, / Their music's mingling waves, / They shake the grass, whose <WSD>pennoned</WSD> spear / Leans on the narrow graves. 
Meaning of the word marked with <WSD> tags:  Bearing one or more pennons (of a pole, spear, mast, etc.).