The term ATTACH SECURELY can be solved by three different crossword solutions: ENROOT (6 letters), AFFIX (5 letters), and GLUE (4 letters). ENROOT means to firmly establish something in a place or situation, while AFFIX means to fasten or join something in a secure manner. Finally, GLUE is a substance used to stick two objects together. All three of these words can be used to describe the action of attaching something securely.