to render futile;  to bring to naught;  to waste;  to not make good use of
 to come to nothing;  to be in vain;  to lead nowhere
 visit for no reason;  go on fool's errand
 economical;  efficient;  lean;  compact
 make good use of;  make the most of
 would be a waste of words;  would be a waste of breath;  there's no point in saying
 economical;  efficient;  lean;  compact
 waste (of money, time, etc.);  squandering;  frittering away
 to come to nothing;  to be in vain;  to lead nowhere
 always listen to your parents;  always value your parents' advice; (lit.) not even one in a thousand of a parents' opinion or an eggplant flower are in vain