no laughing matter (adjective) serious: crucial, weighty
Sinonime: backward, behindhand, belated, dawdling, delayed,
delinquent, detained, dilatory, held up, hung up, in a bind, jammed, laggard, loitering, not arrived, not done, overdue, procrastinating,
retarded,
slack, slow,
sluggish, strapped for time, too late, unpunctual
Antonime: early, on time, prompt, punctual,
ready