[lest] 
| 1. | for fear that; so that (one) should not (used negatively to introduce a clause expressive of an action or occurrence requiring caution): He kept his notes by his side lest faulty memory lead him astray. |
| 2. | that (used after words expressing fear, danger, etc.): There was danger lest the plan become known. |
| lest (lěst) conj. For fear that: tiptoed lest the guard should hear her; anxious lest he become ill. [Middle English, from Old English (thȳ) lǣs the, (whereby) less that, so that not : lǣs, less; see less + the, relative conjunction; see to- in Indo-European roots.] |