The term 'lock up' can refer to a variety of actions, such as the act of confining someone or something in a SECURE place. The crossword solutions for this term include CEMENT (6 letters), ICE (3 letters), CAGE (4 letters), CELL (4 letters), JAIL (4 letters), embar (5 letters), runin (5 letters), SEIZE (5 letters), CLINCH (6 letters), ENCAGE (6 letters), ENSURE (6 letters), FORBID (6 letters), HAMPER (6 letters), SECURE (6 letters), and INCARCERATE (11 letters). These words all describe different ways of restricting access to something or someone, either physically or legally.