Blackett rhymes with:
bracket, brackett, drackett, hackett, jackett, packett, racket, racquet, sackett, shackett, tackett, tackitt
Blackett sounds like:
balked, ballast, belched, bellsouth, belsito, bilked, biologist, blacked, blackest, blackheath, blackout, blackwood, blast, blasted, blazed, bleached, bleakest, blessed, blest, blight, blighted, blissett, blixt, blockade, blockaded, blocked, blockhead, blowiest, bluest, blushed, blust, bolstad, bulged, bulkhead, bullshit