1. replicate, retroflex

bend or turn backward

• replicate

2. retroflex

articulate (a consonant) with the tongue curled back against the palate

Example Sentences:
'Indian accents can be characterized by the fact that speakers retroflex their consonants'

3. retroflex, retroflexed

bent or curved backward

• retroflexed

4. cacuminal, retroflex

pronounced with the tip of the tongue turned back toward the hard palate

• cacuminal