iom
יומ
'iom' appears to refer to a periodic temporal phenomenon. The exact length of time varies with a great degree of flexibility. Although in some cases “today” seems to be the correct implication, in many cases it is used to refer to a person's entire lifespan. In some case it seems to indicate “time” in general.
Despite this wide ranging meaning, most traditional translations have treated the word somewhat differently when it occurs in the opening chapters of Genesis, instead rendering it “day”, and attempting to justify this interpretation with a direct link to the cycle of day and night, light and dark. This interpretation is not necessarily so cut and dry in the original text, as is examined in Genesis 1.
'iom' may or may not be cognate with “eon”.
Technically, a seneh is a subset of an 'iom'.
see also iomim
LexID 3117