Dictionary.com
Thesaurus.com

mother-of-thyme

American  
[muhth-er-uhv-tahym] / ˈmʌð ər əvˈtaɪm /

noun

plural

mother-of-thymes
  1. a branched, woody, prostrate plant, Thymus serpyllum, of the mint family, native to Eurasia and northern Africa, having wiry stems that root at the joints and small, purplish flowers.


Etymology

Origin of mother-of-thyme

First recorded in 1590–1600