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.
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."