Longitude rhymes with:
altitude, amplitude, aptitude, attitude, certitude, exactitude, gratitude, latitude, magnitude, multitude, servitude, solitude, verisimilitude
Longitude sounds like:
lamaist, lanai-city, lancet, lancit, lanctot, langguth, langseth, languid, languished, lanzet, launched, leanest, length, lengthy, leninist, linguist, linked, linquist, linscott, linseed, lionized, longed, longest, longshot, longuet, longwood, lunched, lunged, lynched