lest 
(lĕst)
(lĕst)conj.
1. For fear that: tiptoed lest the guard should hear her; anxious lest he become ill.
2. So that someone or something not; in case someone or something might: "Lest anyone forget, adolescence is purgatory" (Jon Pareles).
[Middle English, from Old English (thȳ) lǣs the, (whereby) less that, so that not : lǣs, less; see LESS + the, relative conjunction; see to- in the Appendix of Indo-European roots.]
- Indo-European root: as-
- Indo-European root: at-
- Indo-European root: au-
- Indo-European root: aug-
- Indo-European root: aus-
- Indo-European root: awi-
- Indo-European root: awo-
- Indo-European root: ayer-
- Indo-European root: ayes-
- Indo-European root: bak-
- Indo-European root: bel-
- Indo-European root: bha-bhā-
- Indo-European root: bhad-
- Indo-European root: bhag-
- Indo-European root: bhardh-ā-
- Indo-European root: bhares-
- Indo-European root: bhau-
- Indo-European root: bhegw-
- Indo-European root: bhei-
- Indo-European root: bheid-
- Indo-European root: bheidh-
- Indo-European root: bhel-
- Indo-European root: bhel-
- Indo-European root: bhel-
- Indo-European root: bhelgh-