Here's what rhymes with invariably.

Consider these alternatives

sometimes / times usually / unusually whenever / never occasionally / educationally tend / end routinely / extremely always / hallways habitually / individually unfortunately / fortunately seem / seen tended / presented ordinarily / necessarily oftentimes / times customarily / necessarily arise / size indeed / need humorous / humerus wherever / never comically / chronically whoever / never infrequently / frequently politely / slightly amusing / using anyway / way polite / right