Tectonic rhymes with:
planktonic, catatonic, diatonic, hypertonic, isotonic, leptonic, miltonic, neoplatonic, planktonic, platonic, plutonic, tonic
Tectonic sounds like:
tajikistan's, tastiness, tasting, tastings, techsystems, tectonics, testimonies, testing, thaxton's, ticketing, tightening, tightenings, tightens, tightness, toasting, touchdowns, twisting