Plural: a bad quarter of an hours
abaction · abactor · abacus · abacuses · Abadan · A bad apology is better than none. · Abaddon · a bad egg · A bad excuse is better than none. · a bad experience · a bad grade · a bad quarter of an hour · A bad workman blames his tools. · abaft · abaft the beam · a bag of nerves · Abakan · abalone · abandon · abandon a child