Bostra rhymes with:
costra, astra, balestra, boonstra, costra, dextra, dykstra, extra, feenstra, hamstra, heemstra, heidstra, hiemstra, hoekstra, hofstra, hukstra, hydstra, kamstra, kustra, lastra, maestra, nostra, olestra, orchestra, rienstra, spoelstra, telstra, terpstra, tuinstra, veenstra, westra, xtra, zandstra, zylstra
Bostra sounds like:
babysitter, backdoor, backwater, bacteria, basketry, bastyr, baxter, bester, bigotry, bistro, bookstore, booster, boster, boughter, buchter, buster, bustier