During the pre-conquest period, the Yaguas could have been in sporadic contact with the Incas, as to this day there are far more Quechua (language spoken by the Inca) words in Yagua than there are Spanish words, another hypothesis points out that Spanish missionaries imposed Quechua as the common language, a customary practice during most of the colony. The term in Quechua would have been something like yawar runa, 'the blood-red people', which could easily have been assimilated into Spanish as yagua.
