The singer laments her precious thyme, which she had and lost. A sailor gave her a rose "that never would decay" to remind her of "the night he stole my bonny thyme away." She warns others against the same mistake
In flower symbolism, thyme stood for virginity. For a catalog of some of the sundry flower symbols, see the notes to "The Broken-Hearted Gardener."
Thyme songs are almost impossible to tell apart, because of course the plot (someone seduces the girl) and the burden (let no man steal your thym) are always identical. For the same reasons, verses float freely between them. So fragmentary versions are almost impossible to classify.
The Digital Tradition has a version, "Rue and Thyme," which seems to have almost all the common elements. Whether it is the ancestor of the various thyme songs, or a gathering together of separate pieces, is not clear to me.
The chorus, "Thyme, it is a precious thing; Thyme brings all things to your mind. Thyme with all its labours Along with all its joys, And it's thyme brings all things to an end," is quite characteristic in its lyric strength. The plot is less diagnostic. - RBW