Definition of yester- in English:

yester-

Pronunciation /ˌyestərˈnīt/ /ˌjɛstərˈnaɪt/

literary, archaic
  • Of yesterday.

    ‘yestereve’
    • ‘yesteryear’

Origin

Old English geostran, of Germanic origin; related to Dutch gisteren and German gestern ‘yesterday’, from an Indo-European root shared by Latin heri and Greek khthes.