From Middle English kepen up, equivalent to keep + up.

keep up (third-person singular simple present keeps up, present participle keeping up, simple past and past participle kept up)

1. (transitive) To maintain; to preserve; to prevent from deteriorating or falling.
   • 1992, The Daily Telegraph, London:

     The NRA is pumping groundwater into the River Itchen in Hampshire to keep up its flow and is trying to save three streams, the Tong, the Little Stour and the Dour from going dry this summer.

2. (transitive, idiomatic) To continue with (work, etc).
   • 1991, Tennis World, Sussex: Presswatch:

     Keep up the good work of entertaining your fans on court Steffi; we know you can do it; your fans are behind you all the way.

   • 1991, Hugh Barty-King, The worst poverty, Gloucester: Alan Sutton Publishing Ltd, pages 85–203:

     If the borrower could no longer afford to keep up the payments, the longer he stayed in the home the more the interest bill mounted.

3. (intransitive, idiomatic) To stay even or ahead.

   They ran so fast I could hardly keep up.

4. To ensure that one remains well-informed about something.

   I always try to keep up with (or "keep up on") current affairs.

5. To prevent someone from going to bed or to sleep

   The crying baby kept me up all night

6. (obsolete, printing) To use capital letters as much as reasonable.

   Antonyms: keep down

• (stay even or ahead) keep pace

• French: maintenir, conserver
• German: erhalten
• Italian: mantenere, conservare
• Portuguese: manter
• Russian: сохранять
• Spanish: mantener, conservar

• French: continuer, maintenir
• German: weitermachen
• Italian: continuare, mantenere
• Portuguese: manter
• Russian: продолжать
• Spanish: continuar

• German: mithalten, Schritt halten
• Italian: stare al passo
• Portuguese: acompanhar, manter-se atualizado
• Spanish: seguir, mantener el ritmo, ir al paso

• Italian: rimanere aggiornato