Subtle rhymes with:
suttle, unsubtle, nuttall, nuttle, rebuttal, ruttle, scuttle, shuttle, suttle, tuttle, unsubtle, what'll
Subtle sounds like:
sheftel, shevtl, sofitel, softly, spatial, spatola, spatula, speedily, speidel, spidel, spidell, spidle, spitale, spittle, subtitle, subtly, swiftly