From Longman Dictionary of Contemporary Englishbiological clockˌbiological ˈclock noun [singular] 1 TMHB technical the system in plants and animals that controls when they sleep, eat, produce babies etc SYN body clock2 HBHthe idea that when a woman reaches a certain age, she will soon be too old to have a baby career women who hear the biological clock ticking
Examples from the Corpus
biological clock• Unlike mechanical clocks, which are completely blind to their surroundings, a biological clock gets reset every day by the sun.• Of course, nature being unjust as ever, I have no biological clock of my own.• The way Max's biological clock is ticking, it's a wonder Emma didn't call out the bomb squad.• It's the men now, as often as not, who hear the biological clock ticking loudest.• The ticking of the biological clock.biological clock ticking• It's the men now, as often as not, who hear the biological clock ticking loudest.