A lock of hair growing just above the forehead.
take time by the forelock seize an opportunity. The Latin fabulist Phaedrus described Opportunity or Occasion as being bald except for a long forelock, a personification that was illustrated in Renaissance emblem books and was also applied to Time.
touch one's forelock indicate respect or deference. From the action of raising a hand to one's forehead in deference when meeting a person of higher social rank (also tug one's forelock).