lest
1. [ adverb ] for fear that
Examples:

"she tiptoed lest her mother should hear her"

2. [ conjunction ] coordinating conjunction, in order that not
3. [ adverb ] that (after verbs explicitly expressing fear etc.)
Examples:

"he worried lest he should be late"

Similar spelling:   Leist
  least
  legato
  legate
  leased
  Leight
  Leicht
  leg_it
  Lesotho
  Legette
  legatee
  Leighty
  Leggitt
  Leggett