Cockburn's rhymes with:
hepburn's, rathburne's, swinburne's, swinburnes, caverns, cisterns, eastern's, governs, hepburn's, interns, irons, lanterns, mcgovern's, moderns, northern's, northwestern's, patterns, rathburne's, saturn's, saturns, severns, southeastern's, southern's, swinburne's, swinburnes, taverns, western's, westerns
Cockburn's sounds like:
cabranes, cabrini's, cavernous, caverns, chaperones, chaperoning, chevron's, copernicus, covering, coverings