lest
Concise Oxford English Dictionary © 2008 Oxford University Press:
lest/lest/
▶conjunction formal
- 1 with the intention of preventing.
- 2 because of the possibility of.
– origin OE thȳ lǣs the ‘whereby less that’, later the læste.
usage: Lest remains one of the very few contexts in English where the subjunctive mood is, strictly speaking, required. Thus the standard use is she was worrying lest he be attacked (not lest he was attacked). See also subjunctive.
'lest' also found in these Oxford entries:
