omer Syllabification: (o·mer)Pronunciation: /ˈōmər, ˈōmer/Definition of omer noun 1an ancient Hebrew dry measure, the tenth part of an ephah. 2 (Omer) Judaism a sheaf of corn or omer of grain presented as an offering on the second day of Passover. the period of 49 days between the second day of Passover and Shavuoth (Pentecost). Origin:from Hebrew ῾ōmeromer in other Oxford dictionaries Definition of omer in the British & World English dictionary