lest /lest/
conjunction literary[
Language: Old English;
Origin: thy læs the 'by which less that']
1. in order to make sure that something will not happen:
She turned away from the window lest anyone see them.2. used to show that someone is afraid or worried that a particular thing might happen
worried/concerned/anxious etc lest ... He paused, afraid lest he say too much. She worried lest he should tell someone what had happened. [TahlilGaran] Dictionary of Contemporary English ▲