What is the meaning of the word "baby's tears"?

Definitions:

  1. A small, creeping plant with tiny, round leaves that form a dense mat, often used as a ground cover in gardens or as a decorative plant in terraniums and indoor planters. copy to clipboard NOUN
    • The baby's tears plant added a lush, green touch to the terranium, spreading quickly over the rocks. copy to clipboard
  2. Prostrate or creeping Corsican herb with moss-like small round short-stemmed leaves. copy to clipboard NOUN
    • She planted baby's tears around the base of the bonsai tree to create a natural, verdant landscape. copy to clipboard
  3. The actual tears shed by a baby when crying. copy to clipboard NOUN
    • The mother's heart melted at the sound of her baby's tears, a bittersweet reminder of their bond. copy to clipboard

Synonyms: