1) Assure 2) Calm 3) Calm down 4) Cause to feel sure 5) Cause to feel sure or certain 6) Comfort 7) Comfort verbally 8) Encourage 9) Enhearten 10) French word used in English 11) Give back confidence 12) Give back confidence to 13) Give comfort to 14) Give confidence to 15) Give new confidence to 16) Give or restore confidence in Found on https://www.crosswordclues.com/clue/reassure
Re`as·sure' (rē`ȧ*shur') transitive verb 1. To assure anew; to restore confidence to; to free from fear or terror. « They rose with fear, . . . Till dauntless Pallas reassured the rest.» Dryden. 2. To reinsure. Found on http://www.encyclo.co.uk/webster/R/20