early 13c., from weak grade of Old English teohan "to pull, drag," from Proto-Germanic *teukh- "pull," from PIE *deuk- "to pull, to lead" (see duke (n.)). Related to tow (v.). Related: Tugged; tugging.
tug
n.
c.1500, from tug (v.). Meaning "small steamer used to tow other vessels" is recorded from 1817. Phrase tug of war (1670s) was originally figurative, "the decisive contest, the real struggle."