In lang=en terms the difference between lengthen and drawl
is that
lengthen is to become longer while
drawl is to speak with a slow, spiritless utterance, from affectation, laziness, or lack of interest.
As verbs the difference between lengthen and drawl
is that
lengthen is to make longer, to extend the length of while
drawl is to drag on slowly and heavily; while or dawdle away time indolently.
As a noun drawl is
a way of speaking slowly while lengthening vowel sounds and running words together characteristic of some.