WordNet sense 1 (any thick messy substance):

goo, gunk, muck, slime, sludge, guck

WordNet sense 2 (the process of seeping):

seepage, oozing

WordNet sense 3 (pass gradually or leak through or as if through small openings):

seep

WordNet sense 4 (release (a liquid) in drops or small quantities):

exude, exudate, transude, ooze out