What's the difference between erst and once?

Erst


Definition:

  • (adv.) First.
  • (adv.) Previously; before; formerly; heretofore.

Example Sentences:

  • (1) The magnetic field intensity was 500 and 1000-1500 ersted and the microbial load was 1, 10 and 100 thous.
  • (2) During an exposure of animals to a constant magnetic field of 1000 and 4500 ersted changes in the hypothalamic-hypophyseal system were noted.
  • (3) Pharmacy has shed the apothecary role but has not yet been restored to its erst-while importance in medical care.
  • (4) A repeated influence (30 min a day) of the strong magnetic field of 912 ersted for 16 days inhibits synthetic processes in the liver tissue.
  • (5) A study was made of the 131I radioisotope absorption by the thyroid gland, thyroxin binding by a number of tissues, and also protein-bound iodine (PBI) content in the blood plasma of albino rats after the application of alternating magnetic field (AMF)--industrial frequency 200 Ersted voltage--of various duration and periodicity.

Once


Definition:

  • (adv.) By limitation to the number one; for one time; not twice nor any number of times more than one.
  • (adv.) At some one period of time; -- used indefinitely.
  • (adv.) At any one time; -- often nearly equivalent to ever, if ever, or whenever; as, once kindled, it may not be quenched.

Example Sentences:

Words possibly related to "erst"