Words That Rhyme With "Spontaneously" :

4 syllables:

aqueously, cranially

5 syllables:

cutaneously, erroneously, euphoniously, extraneously, feloniously, harmoniously, symphoniously

6 syllables:

acrimoniously, ceremoniously, coetaneously, homogeneously, ignominiously, parsimoniously, sanctimoniously, simultaneously, subcutaneously, unharmoniously

7 syllables:

contemporaneously, extemporaneously, heterogeneously, inhomogeneously, intracutaneously, unceremoniously