What rhymes with extension? These are words that rhyme with extension. See also Rhyme Poems and How many syllables are in extension?
gentian, henschen, mention, pension, tension
ascension, attention, contention, convention, detention, dimension, dissension, extension, invention, laurentian, pretension, prevention, retention, suspension
apprehension, comprehension, condescension, hypertension, hypotension, reinvention
misapprehension