towline vs towing rope

towline and towing rope both are nouns.

Word	Noun	Adjective	Verb	Adverb
towline	Yes	No	No	No
towing rope	Yes	No	No	No

As nouns, towline and towing rope are synonyms defined as:

Other synonyms of towline include towing line, towrope.

towline (noun)	towing rope (noun)
(nautical) a rope used in towing	(nautical) a rope used in towing