The term 'assure' can be defined as to make certain or to give confidence to someone. The crossword solutions for this term include 'CONFIRM' (7 letters), 'HEARTEN' (7 letters), 'CINCH' (5 letters), 'PERSUADE' (8 letters), 'REASSURE' (8 letters), 'INSURE' (6 letters), 'ENSURE' (6 letters), 'VOUCH' (5 letters), 'ASSEVERATE' (10 letters), 'DECLARE' (7 letters), 'AVER' (4 letters), 'VOW' (3 letters), 'ATTEST' (6 letters), 'SWEAR' (5 letters), 'SEAL' (4 letters), 'ICE' (3 letters), and 'sewup' (5 letters), and 'CERTIFY' (7 letters). All of these words can be used to express the idea of making something certain or giving someone confidence. For example, 'CONFIRM' can be used to CONFIRM a statement or agreement, 'HEARTEN' can be used to give someone courage or hope, 'CINCH' can be used to make something certain or easy, 'PERSUADE' can be used to convince someone of something, 'REASSURE' can be used to give someone reassurance, 'INSURE' and 'ENSURE' can be used to make sure something happens, 'VOUCH' can be used to guarantee something, 'ASSEVERATE' can be used to state something emphatically, 'DECLARE' can be used to make a formal announcement, 'AVER' can be used to state something as a fact, 'VOW' can be used to make a solemn promise, 'ATTEST' can be used to testify to the truth of something, 'SWEAR' can be used to make a solemn promise, 'SEAL' can be used to make something secure, 'ICE' can be used to make something certain, 'sewup' can be used to make something certain or complete, and 'CERTIFY' can be used to ATTEST to the truth or accuracy of something.