Headroom rhymes with:
bedroom, bedroom, boardroom, backroom, ballroom, barroom, bathroom, bedroom, boardroom, bridegroom, classroom, cloakroom, courtroom, darkroom, elbowroom, livingroom, lunchroom, mailroom, newsroom, playroom, restroom, schoolroom, stockroom, storeroom, sunroom, toolroom, washroom, workroom
Headroom sounds like:
hadrian, hathorn, hathorne, hawthorn, hawthorne, heidorn, hydron