Viscous
So much more fun to say and write than thick, viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress (from Wikipedia), but like any great word, it can be applied poetically to mean many more varied and interesting things.
vis·cous [vis-kuhs] adj. having a thick, sticky consistency between solid and liquid; having high viscosity
Synonyms: sticky, viscid, glutinous, gluey, adhesive, gummy, syrupy
Etymology: late 14c., from Anglo-Fr. viscous, from L.L. viscosus "sticky," from L. viscum "anything sticky, birdlime made from mistletoe, mistletoe," probably from PIE root *weis- "to melt away, flow" (used of foul or malodorous fluids); see virus.
