Words That Rhyme With "External" :
2 syllables:
Bernal, carnal, charnel, colonel, darnel, journal, kernel, sternal, tarnal, vernal
3 syllables:
asternal, diurnal, eternal, fraternal, hibernal, infernal, internal, maternal, nocturnal, paternal, supernal
4 syllables:
coeternal, hodiernal, retrosternal, sempiternal