homeophony
Phonic similarity; the quality of being similar-sounding.
uncountable
It may be styled euphonic, because it seems to affect words solely for the sake of euphony, or, rather, homœophony, and on the mere ground of contiguity in location, although very remotely related in all other respects; so much so, that, in this way, great violence is sometimes done to the true grammatical construction.
Where it comes from
From homeo- + -phony; equivalent to the Ancient Greek ὅμοιος (hómoios, “similar”) + φωνή (phōnḗ, “sound”).
Adapted from the Wiktionary entry homeophony (CC BY-SA 4.0).