This is the 18291st most frequent Russian word.
шестиметровую
"Шестиметровую" means "six-meter" (describing something that is six meters long).
In this sentence, 'шестиметровую' is an adjective describing the noun 'верёвку' (rope), indicating its length.
Учитель приобрёл шестиметровую верёвку для занятий на улице.
The teacher acquired a six-meter-long rope for outdoor activities.
Here, 'шестиметровую' acts as an adjective modifying 'стену' (wall), specifying its height.
Строительство шестиметровую стену завершилось на прошлой неделе.
The construction of the six-meter wall was completed last week.
In this context, 'шестиметровую' describes 'лодку' (boat), referring to its length.