Definition of preform in English:

preform

verb

[WITH OBJECT]
  • Form (something) beforehand.

    ‘a preformed pool’
    • ‘Nitrogen is more soluble than helium and any preformed bubbles will quickly absorb nitrogen.’
    • ‘Short and medium shoots were self-terminated and had only preformed nodes.’
    • ‘Organs developed in this way are referred to as preformed organs.’
    • ‘Preformed ponds and pond kits are two perfect ways to accent your backyard.’

Pronunciation:

preform

/ˌprēˈfôrm/