LUO4, HOU4 to fall behind, to lag (in technology etc), backward, to retrogress
后代
HOU4, DAI4 posterity, later periods, later ages, later generations
后顾之忧
HOU4, GU4, ZHI1, YOU1 fears of trouble in the rear (idiom), family worries (obstructing freedom of action), worries about the future consequences, often in negative expressions, meaning 'no worries about anything'